问答题

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistDo the following statements agree with the claims of the writer in Reading Passage 2 In boxes on your answer sheet, write YES if the statement agrees with the claims of the writer NO if the statement contradicts the claims of the writer NOT GIVEN if it is impossible to say what the writer thinks about this People need to buy gifts for each other in Secret Santa Game.

答案： NO

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You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—GuardianComplete the summary using the list of words, A-Q, below. Write the correct letter, A-Q, in boxes on your answer sheet. Experts in the Natural History Museum plan to visit a place locating in northern Paraguay, Bolivia and Argentina which is called 1 in the next period of time. The area is also known as 2 The visiting reason is that it is the place where is full of 3 and until now it has not been 4 In this forest whose size is about 5 of Britain, there are a wide variety of plants and animals, including Jaguars, 6 and 7 However, due to the sudden contact, it not only brings the local indigenous people 8 , but also produces negative effects on the 9 and 10 of their territory. As for the visitors, travel is also not safe, as there were 11 occurred before in 1979 and 1986. Therefore, this 12 exploration is proposed to abolish. A infection B giant anteaters C stability D high-risk E twice F explored G Gran Chaco H violence I giant otters J green hall K biodiversity L integrity M isolated N hospitable O indigenous P accidental Q half

答案： G

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistDo the following statements agree with the claims of the writer in Reading Passage 2 In boxes on your answer sheet, write YES if the statement agrees with the claims of the writer NO if the statement contradicts the claims of the writer NOT GIVEN if it is impossible to say what the writer thinks about this People need to buy gifts for each other in Secret Santa Game.

答案： NO

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning HeraldLook at the following descriptions and the list of people below. Match each description with the correct person, A-E. Write the correct letter, A-E, in boxes on your answer sheet. NB You may use any letter more than once. List of People A Jim Bowler B Alan Thorne C Chris Stringer D Rainer Grun E Tim Flannery the supporter of multi-regional explanation, which was raised to replace the single source origin

答案： B

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： J

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistSecret Santa is more reasonable than thieving Santa.

答案： NOT GIVEN

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning Heraldan advocate of the idea that Bowler’s research was the most rigorous one for the ancient human remains

答案： E

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： K

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistThe disadvantage of thieving Santa is that the first player always gets the worst gift.

答案： NO

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning Heraldthe researcher who identified the age of Mungo Man was much younger than former result, earlier than 62,000 years

答案： A

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： F

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistIt is possible that expected utility is effective theoretically.

答案： YES

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning Heraldthe researcher who searched for ancient lakes and came across the charred remains of Mungo Lady who had been cremated

答案： A

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： E

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistGhosh and Mahdian can get final strategy to thieving Santa through backward induction.

答案： YES

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning Heraldthe researcher who reminds that research community would be satisfied if more researches could be done to draw the final conclusion

答案： C

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： B(或I)

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistThe threshold in the ’threshold strategy’ becomes higher along with the process of the game.

答案： YES

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning Heraldthe researcher who showed a different attitude towards the reliability of DNA analysis on some fossils

答案： C

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： I(或B)

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistComplete each sentence with the correct ending, A-M, below. Write the correct letter, A-M, in boxes on your answer sheet. A only play the simplified version of the game. B will shape players into thefts. C uses ’backward induction’ to analyse the game. D is more interesting than the traditional game. E has the same opportunity of choosing as others. F can calculate the value of gifts each player gets accurately. G has one more chance to play, which may avoid the inequality of the game. H can succeed finally. I becomes the sacrifice of the game which can not be changed any more. J played thieving Santa at a party. K make people design variants. L is that the final player can get the worst gift. M can use ’threshold strategy’ to estimate the value of the gifts left in order to make a smarter choice. Thieving Santa

答案： D

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistThe drawback of thieving Santa

答案： K

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning Heraldthe researcher who identified that the debate over the age of Mungo Man was unnecessary due to the findings in China

答案： B

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： A

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistGhosh and Mahdian

答案： C

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning Heraldthe researcher who used three techniques to analyse the dating of Mungo Man

答案： B

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： L(或C)

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistThe final player

答案： M

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning HeraldDo the following statements agree with the claims of the writer in the Reading Passage 3 In boxes on your answer sheet, write YES if the statement agrees with the claims of the writer NO if the statement contradicts the claims of the writer NOT GIVEN if it is impossible to say what the writer thinks about this Archaeologists’ theory about the living place of Mungo Man is based on the three important kinds of fossils.

答案：正确

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： C(或L)

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistThe second player

答案： E

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning HeraldMungo Man’s right elbow was damaged more seriously than the left one.

答案： NOT GIVEN

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： H

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistThe first player

答案： G

单项选择题

The Secret of Secret Santa
A When it comes to Christmas presents, do you give as good as you get Most people think they do. Even President Barack Obama is on record saying he goes one better. ’Here’s the general rule: I give nicer stuff than I get,’ he told Oprah Winfrey in a pre-Christmas interview last year. That may seem ungrateful, but consider the implications. Most people believe that the gifts they get are not as good as the ones they give. No wonder Christmas is so often a crushing disappointment.
B There is a better way: abandon the ritual of mutual gift-giving in favour of a much more rational system called secret Santa. The beauty of this is that you only have to buy one present for each social circle you belong to, rather than one for everyone you know.
C In the original version of secret Santa each member of a group—colleagues, say—is anonymously assigned to buy a gift for another and give it to them at the Christmas party. Thankfully, that game has evolved into something more Machiavellian: thieving Santa, also known as dirty Santa or the Grinch game. As its name suggests, this revolves around theft and dirty tricks. In its simplest version, everybody buys a present costing between, say, ￡10 and ￡20. They then secretly deposit it, gift-wrapped, into a sack. To start the game, numbers are drawn out of a hat to decide the order of play.
D Now the horse-trading begins. The first player must take a present from the sack and open it. The second player then has a choice—open a new present, or steal the already opened one. If they choose to steal, player 1 gets to open another present, but they are not allowed to steal their present straight back. Player 3 now enters the fray, either opening a new present or stealing an opened one, whereupon the victim gets to play again, either stealing a different present or opening another new one. And so it goes on until everybody has had a turn and there are no more unopened presents.
E The system is not without its flaws, however. For example, if the first player opens a poor present they are likely to be stuck with it, while the player picked to go last has a good chance of getting a really good present, perhaps the best. For that reason there are many variants designed to spread the pain. One is to allow dispossessed players to steal a present back, although this tends to lead to endless rounds of tit-for-tat larceny. Another is to set a limit on how many times an individual present can be stolen.
F If you have never played thieving Santa, give it a go. It’s fun. Fun, though, can be overrated. What you really want is to win—and that means ending up with the best possible present. So how should you 8o about getting it Imagine you are playing a game in which a present can only be stolen once and it is your turn. There are three opened presents on the table and four in the sack. One of the opened ones is not bad, and if you steal it you can keep it. But there may be even better ones in the sack, so why not gamble Then again, if you open a really good present somebody is certain to steal it from you, and you risk ending up with something really terrible. What to do
G Here is where a strategy developed by game theorists Arpita Ghosh and Mohammad Mahdian of Yahoo Research in Santa Clara, California, can help. ’I heard about this game at a New Year’s party, from somebody who had just been playing it at Christmas,’ says Ghosh. ’I thought it would be fun to analyse.’
H Ghosh and Mahdian decided to play a simplified version of the game. Assuming certain things—that the players are sober, for example, and that everybody puts the same value on the same presents. They wanted to work out how to ’maximise the expected utility’. Or, in English, to work out what you theoretically expect to get out of a transaction before it has happened. They started by thinking about the game’s final round, where all but one of the players has had a turn and there is just one unopened present left in the sack. In this case the strategy is pretty obvious. If all the presents are worth somewhere between ￡10 and ￡20, the expected value of the final unopened present is ￡15. The rational strategy, therefore, is to look around the table and steal any present worth more than that. But remember, if the top present has been unwrapped it is likely to have been stolen already so you won’t be able to have it. So if there isn’t a present worth more than ￡15 that hasn’t already been stolen, open the one in the sack. This means that the final player has an expected utility of at least ￡15, which is about as good as it gets. Expected utility, of course, is not the same as what you actually get. You might think that the final present is trash, in which case the strategy wasn’t much help. But at least you can console yourself that it was correct in theory.
I Ghosh and Mahdian then started to work backwards through each player’s turn—a process known as backward induction—to derive a general strategy. Their next stop was the last-but-one player, where there are two unopened presents. This is a bit more complicated than before, as you have to take into account the possibility of opening a really good present which is immediately stolen. This possibility means that the last-but-one player must have a lower steal threshold than the final player. Ghosh and Mahdian’s calculations show that a player in this position should steal any present worth ￡13.75 or more. If there is no such present available, they should open a new one. This ’threshold strategy’ turns out to work for all players, except the first, who has no choice but to open an unopened gift. The steal threshold itself rises as each player takes their turn because the fewer people left to pick a present, the fewer opportunities there are for someone to steal yours. What this means is the steal threshold starts low; in an 8-player game it is approximately 11.56 for the second player. But, surprisingly, it delivers an expected utility of slightly more than ￡15 for all players—except poor old player 1, of course, who is more or less guaranteed to ’take one for the team’ and get something pretty lousy.
J ’When your turn arrives, have a look at the gifts that you can possibly steal,’ says Ghosh. ’If the best of those is good enough, where "good enough" depends on how many unopened gifts remain, steal it. If the best of those is not good enough, open a new gift. What this is really all about is making sure you get the best of the rubbish.’ This should perhaps be known as ’minimising your futility’, Ghosh said. So what of the first player, who seems doomed to pick the short straw This is an acknowledged problem in real-world thieving Santa, and is usually solved by giving the first player a chance to steal right at the end. In this case all the players have an expected utility of exactly ￡15. With all this strategy at her fingertips, you would expect Ghosh to be arranging secret Santa games every year. ’Actually no,’ she says. ’I’ve never played it.’ Typical theorist.
—New ScientistChoose the correct letter, A, B, C or D. Write the correct letter in box on your answer sheet. Which of the following is the main idea of Reading Passage 2

A. the relationship between secret Santa and thieving Santa
B. the suggestions for the first player in the thieving Santa
C. what the secret of Santa games is and the improvement suggested
D. how to get the best gift when playing games

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning HeraldMuch more evidence shows that the ancestors originated from Africa rather than from Australia.

答案：正确

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—Guardian

答案： D

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning HeraldThe new Mungo dates showed the time of megafaura’s extinction in Australia.

答案：正确

单项选择题

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.
Natural History Museum Expedition ’Poses Genocide Threat’ to Paraguay Tribes
Anthropologists and indigenous leaders have warned that a Natural History Museum expedition to Paraguay could lead to ’genocide’ and are calling for it to be abandoned. They fear that the scientists and their teams of assistants are likely to make accidental contact with isolated indigenous groups in the remote region they are planning to visit and could pass on infectious diseases.
The expedition is due to set off in the next few days for two of the remotest regions of the vast dry forest known as the Gran Chaco, which stretches over northern Paraguay, Bolivia and Argentina. The expedition organisers hope to find several hundred new species of plants and insects. But the two sites where the British and Paraguayan teams of botanists, biologists and other scientists plan to stay in for up to a month are known to be home to groups of Ayoreo Indians. They live in voluntary isolation and reject and avoid all contact with Westerners, said Benno Glauser, director of leading indigenous peoples’ protection group Iniciativa Amotocodie.
Glauser, with the backing of Ayoreo leaders who have left the forest in the last 20 years, has sent the museum more than 40 pieces of data showing the presence of isolated peoples in the Chovoreca and Cabrera Timane regions. ’According to our data, the expedition you plan constitutes beyond any doubt an extremely high risk for the integrity, safety and legal rights of life and self-determination of the isolated Ayoreo, as well as for the integrity and stability of their territories. There exists a considerable menace and risk also for the safety of the scientists taking part of the expedition, as well as the rest of expedition participants,’ says Glauser in a letter to the museum.
Until about 1950 it is estimated that around 5,000 Ayoreo lived in the Chaco forest as isolated hunter-gatherers without contact with the ranchers and religious groups who were given land by the Paraguayan government. Since then almost all have left the forest after being targeted by American missionaries. It is estimated that there are now only six or seven isolated groups numbering around 150 people in total. It is now the only place in South America outside the Amazon where uncontacted Indians still live.
Ayoreo leaders who have settled near the town of Filadelfia in northern Paraguay this week appealed to the president of Paraguay and the Natural History Museum to abandon the expedition, saying that their relatives were in grave danger. ’Both of these regions belong to the Ayoreo indigenous territory... We know that our people still live in the forest and they don’t want to leave it to join white civilisation.’ He said there are at least three uncontacted groups in the area. ’If this expedition goes ahead we will not be able to understand why you prefer to lose human lives just because the English scientists want to study plants and animals. There is too much risk: the people in the forest die frequently from catching white people’s diseases. Because the white people leave their rubbish, their clothes, or other contaminated things. It’s very serious. It’s like a genocide,’ they said in a statement.
According to Survival International, a NGO that campaigns for the rights of tribal peoples, contact with any isolated Indians would be disastrous for either party. ’Contact with isolated groups is invariably violent, sometimes fatal and always disastrous,’ said Jonathan Mazower, a spokesman. ’It is highly likely that there are small groups of isolated Indians scattered throughout the Chaco. The only sensible thing to do is err on the side of caution because any accidental contact can be disastrous. This has happened before [in the Chaco]. On two previous occasions, in 1979 and 1986 expeditions were sent in by U.S. missionaries to bring out Indians and people were killed on both occasions.’
The expedition, one of the largest undertaken by the museum in more than 50 years, has taken several years to plan and is believed to be costing more than ￡300,000. It hopes to map and record species of thousands of plants and insects, which will then go to local Paraguayan museums. Until last month, the museum’s website had claimed that the area the scientists will visit ’has not been explored by human beings’. This created consternation in the Ayoreo communities. ’Some people say they are going to places in which no human being has ever been. That means we Ayoreo are not human beings,’ said one of the leaders in a statement to the Guardian. ’Our uncontacted brothers have the right to decide how they want to live—if they want to leave or not.’
The Chaco, known as ’green hell’ is one of the least hospitable but most biologically diverse places on Earth. The barely populated expanse of almost impenetrable forest is twice the size of the UK, but home to at least 3,400 plant species, 500 bird species, 150 species of mammals, 120 species of reptiles, and 100 species of amphibians. Jaguars, pumas, giant anteaters and giant otters are common.
In a statement, the Natural History Museum said it had planned the expedition in conjunction with the Paraguayan government and would be working with Ayoreo Indians. It continued: ’We are delighted to be working with representatives of the indigenous people. This gives us a wonderful opportunity to combine traditionally acquired knowledge with scientifically acquired knowledge to our mutual benefit. As with all expeditions, the team is continually reviewing the situation. Our primary concern is for the welfare of the members of the expedition team and the people of the Dry Chaco region.’
—GuardianChoose the correct letter, A, B, C or D. Write the correct letter in box 13 on your answer sheet. Which of the following is the main idea of Reading Passage 1

A. The planned expedition of Natural History Museum to Paraguay has been banned.
B. The expedition of Natural History Museum may have negative effects on the Dry Chaco region.
C. The expedition of Natural History Museum may be a wonderful opportunity for people to get a better understanding of the Dry Chaco region.
D. There are really some people living in Ayereo, who can help researchers study the culture there.

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning HeraldClimate change is the only reason for megafaura’s extinction.

答案：错误

Dawn in Our Garden of Eden
The latest research suggests Australia’s Adam and Eve are not as old as we thought—and lived much richer lives than we suspected.
A Fifty thousand years ago, a lush landscape greeted the first Australians making their way towards the south-east of the continent. Temperatures were cooler than now. Megafauna—giant prehistoric animals such as marsupial lions, goannas and the rhinoceros-sized diprotodon—were abundant. The Lake Mungo remains are three prominent sets of fossils which tell the archeologists the story: Mungo Man lived around the shores of Lake Mung with his family. When he was young, Mungo Man lost his two lower canine teeth, possible knocked out in a ritual. He grew into a man nearly 1.7m in height. Over the years his molar teeth became worn and scratched, possibly from eating a gritty diet or stripping the long leaves of water reeds with his teeth to make twine. As Mungo Man grew older his bones ached with arthritis, especially his right elbow, which was so damaged that bits of bone were completely worn out or broken away. Such wear and tear is typical of people who have used a woomera to throw spears over many years. Mungo Man reached a good age for the hard life of a hunter-gatherer, and died when he was about 50. His family mourned for him, and carefully buried him in the lunette, on his back with his hands crossed in his lap, and sprinkled with red ochre. Mungo Man is the oldest known example in the world of such a ritual.
B This treasure-trove of history was found by the University of Melbourne geologist Professor Jim Bowler in 1969. He was searching for ancient lakes and came across the charred remains of Mungo Lady, who had been cremated. And in 1974, he found a second complete skeleton, Mungo Man, buried 300 metres away. Using carbon- dating, a technique only reliable to around 40,000 years old, the skeleton was first estimated at 28,000 to 32,000 years old. The comprehensive study of 25 different sediment layers at Mungo concludes that both graves are 40,000 years old.
C This is much younger than the 62,000 years Mungo Man was attributed with in 1999 by a team led by Professor Alan Thorne, of the Australian National University. The modern day story of the science of Mungo also has its fair share of rivalry. Because Thorne is the country’s leading opponent of the Out of Africa theory—that Homo sapiens had single place of origin. Dr. Alan Thorne supports the multi-regional explanation (that modern humans arose simultaneously in Africa, Europe and Asia from one of our predecessors, Homo erectus, who left Africa more than 1.5 million years ago.) If Mungo Man was descended from a person who had left Africa in the past 200,000 years, Thorne argues, ’then his mitochondrial DNA should have looked like that of the other samples.’
D However, Out of Africa supporters are not about to let go of their beliefs because of the Australian research, Professor Chris Stringer, from the Natural History Museum in London, UK, said that the research community would want to see the work repeated in other labs before major conclusions were drawn from the Australian research. But even assuming the DNA sequences were correct, Professor Stringer said it could just mean that there was much more genetic diversity in the past than was previously realised. There is no evidence here that the ancestry of these Australian fossils goes back a million or two million years. It’s much more likely that modern humans came out of Africa. For Bowler, these debates are irritating speculative distractions from the study’s main findings. At 40,000 years old, Mungo Man and Mungo Lady remain Australia’s oldest human burials and the earliest evidence on Earth of cultural sophistication, he says. Modern humans had not even reached North America by this time. In 1997, Pddbo’s research group recovered amtDNA fingerprint from the Feldholer Neanderthal skeleton uncovered in Germany in 1865—the first Neanderthal remains ever found.
E In its 1999 study, Thorne’s team used three techniques to date Mungo Man at 62,000 years old, and it stands by its figures. It dated bone, teeth enamel and some sand. Bowler has strongly challenged the results ever since. Dating human bones is ’notoriously unreliable’, he says. As well, the sand sample Thorne’s group dated was taken hundreds of metres from the burial site. ’You don’t have to be a gravedigger... to realise the age of the sand is not the same as the age of the grave,’ says Bowler.
F Thorne counters that Bowler’s team used one dating technique, while his used three. Best practice is to have at least two methods produce the same result. A Thorne team member, Professor Rainer Grin, says the fact that the latest results were consistent between laboratories doesn’t mean they are absolutely correct. ’We now have two data sets that are contradictory. I do not have a plausible explanation.’ Now, however, Thorne says the age of Mungo Man is irrelevant to this origins debate. Recent fossils finds show modern humans were in China 110,000 years ago. So he has got a long time to turn up in Australia. It doesn’t matter if he is 40,000 or 60,000 years old.
G Dr. Tim Flannery, a proponent of the controversial theory that Australia’s megafauna was wiped out 46,000 years ago in a ’blitzkrieg’ of huntingg by the arriving people, also claims the new Mungo dates support this view. In 2001 a member of Bowler’s team, Dr. Richard Roberts of Wollongong University, along with Flannery, director of the South Australian Museum, published research on their blitzkrieg theory. They dated 28 sites across the continent, arguing their analysis showed the megafauna died out suddenly 46,000 years ago. Flannery praises the Bowler team’s research on Mungo Man as ’the most thorough and rigorous dating of ancient human remains’. He says the finding that humans arrived at Lake Mungo between 46,000 and 50,000 years ago was a critical time in Australia’s history. There is no evidence of a dramatic climatic change then, he says. ’It’s my view that humans arrived and extinction took place in almost the same geological instant.’
H Bowler, however, is skeptical of Flannery’s theory and says the Mungo study provides no definitive new evidence to support it. He argues that climate change at 40,000 years ago was more intense than had been previously realised and could have played a role in the megafauna’s demise. ’To blame the earliest Australians for their complete extinction is drawing a long bow.’
—The Sydney Morning HeraldThe consistency of the study results of both Bowler and Thorne may persuade the research community.

答案： NOT GIVEN