Researchers Discover Why Humans Began Walking Upright

    Most of us walk and carry items in our hands every day. These are seemingly simple activities that the majority of us don’t uestion. But an international team of researchers,including Dr. ichmond from GW"s Columbian College of Arts and Sciences，have discovered that human walking upright, may have originated millions of years ago as an adaptation to carrying scarce, high-quality resources. The team of researchers from the U.S., England, Japan and Portugal investigated the behavior of modern-day himpanzees as they competed for food resources,an effort to understand what ecological settings wouldin lead a large ape — one that resembles the 6 million-year old ancestor we shared in common with living chimpanzees — to walk on two legs.

    “These chimpanzees provide a model of the ecological conditions under which our earliest ancestors might have begun walking on two legs, "，said Dr. Richmond.

    The research findings suggest that chimpanzees switch to moving on two limbs instead of four in situations where they need to monopolize a resource. Standing on two legs allows them to carry much more at one time because it frees up their hands. Over time，intense bursts of bipedal activity may have led to anatomical changes that in turn became the subject of natural selection where competition for food or other resources was strong.

    Two studies were conducted by the team in Guinea. The first study was conducted by the team in Kyoto University’s “ outdoor laboratory ” in a natural clearing in Bossou Forest. Researchers allowed the wild chimpanzees access to different combinations of two different types of nut — the oil palm nut，which is naturally widely available, and the coula nut, which is not. The chimpanzees’ behavior was monitored in three situations:(a) when only oil palm nuts were available,(b)when a small number of coula nuts were available， and(c) when coula nuts were the majority available resource.

    When the rare coula nuts were available only in small numbers, the chimpanzees transported more at one time. Similarly, when coula nuts were the majority resource, the chimpanzees ignored the oil palm nuts altogether. The chimpanzees regarded the coula nuts as a more highly-prized resource and competed for them more intensely.

    In such high-competition settings，the frequency of cases in which the chimpanzees started moving on two legs increased by a factor of four. Not only was it obvious that bipedal movement allowed them to carry more of this precious resource, but also that they were actively trying to move as much as they could in one go by using everything available 一 even their mouths.

    The second study, by Kimberley Hockings of Oxford Brookes University, was a 14-month study of Bossou chimpanzees crop-raiding, a situation in which they have to compete for rare and unpredictable Resources. Here, 35 percent of the chimpanzees activity involved some sort of bipedal movement, and once again, this behavior appeared to be linked to a clear attempt to carry as much as possible at one time.

词汇：

scarce / skeəs/ vt. adj.缺乏的，不足的；稀有的
chimpanzee /ˌtʃɪmpæn"zi:/ n.黑猩猩
ape /eɪp/ n.无尾猿; 类人猿
bipedal /ˌbaɪˈpi:dl/ adj. 二足的
anatomical /ˌænə"tɒmɪkl/ adj.解剖的
coula nuts( coula也可写作cola或kola)可乐果

注释：

1. GW’s Columbian College of Arts and Sciences:乔治？华盛顿大学哥伦比亚艺术与科学学院。乔治·华盛顿大学（George Washington University)的英文简称为 GW，是美国顶尖的私立大学之一，于 1821 年建校，位于美国首都华盛顿。

2. ecological settings: 生态环境

3. bipedal activity：双足活动

4. anatomical chaiige: 解剖学上的变化

5. Kyoto University:京都大学，是继东京大学之后成立的日本第二所国立大学，于I897 年建校。京都大学主要校区位于日本历史名城京都市。

6. Bossou: 博苏,几内亚的一个地名。博苏森林生活着黑猩猩群落。

7. oil palm nut: 油棕榈坚果

8. increased by a factor of four:增加了四倍

9. in one go: —口气

10. Oxford Brookes University: 牛津布鲁克斯大学，创立于 1865 年，是英国最具特色的综合性大学之一。牛津布鲁克斯大学位于世界学术名城——牛津。这里学风浓郁、精英荟萃，历来为求学圣地。

Why did the chimpanzees walk on two limbs during Kyoto University"s experiment?

A:Because they imitated the human way of walking just for fun. B:Because they wanted to please the researchers to get more coula nuts from them. C:Because they wanted to get to die nut-rich forest faster by walking that way. D:Because they wanted to carry more nuts with two free limbs.

(Human) society, (or in any) community, (may be spoken) (of as) a social organism.

A:Human B:or in any C:may be spoken D:of as

Most of us walk and carry items in our hands every day. These are seemingly simple activities that the majority of us don’t question. But an international team of researchers, including Dr. Richmond from GW’s Columbian College of Arts and Sciences, have discovered that human walking upright, may have originated millions of years ago as an adaptation to carrying scarce, high-quality resources. The team of researchers from the US, England, Japan and Portugal investigated the behavior of modern-day chimpanzees as they competed for food resources, in an effort to understand what ecological settings would lead a large ape—one that resembles the 6 million-year old ancestor we shared in common with living chimpanzees—to walk on two legs.
"These chimpanzees provide a model of the ecological conditions under which our earliest ancestors might have begun walking on two legs ", said Dr. Richmond.
The research findings suggest that chimpanzees switch to moving on two limbs instead of four in situations where they need to monopolize a resource. Standing on two legs allows them to carry much more at one time because it frees up their hands. Over time, intense bursts of bipedal activity may have led to anatomical changes that in turn became the subject of natural selection where competition for food or other resources was strong.
Two studies were conducted by the team in Guinea. The first study was conducted by the team in Kyoto University’s "outdoor laboratory" in a natural clearing in Bossou Forest. Researchers allowed the wild chimpanzees access to different combinations of two different types of nut—the oil palm nut, which is naturally widely available, and the coula nut, which is not. The chimpanzees’ behavior was monitored in three situations: (a) when only oil palm nuts were available, (b)when a small number of coula nuts were available, and(c) when coula nuts were the majority available resource.
When the rare coula nuts were available only in small numbers, the chimpanzees transported more at one time. Similarly, when coula nuts were the majority resource, the chimpanzees ignored the oil palm nuts altogether. The chimpanzees regarded the coula nuts as a more highly-prized resource and competed for them more intensely.
In such high-competition settings, the frequency of cases in which the chimpanzees started moving on two legs increased by a factor of four. Not only was it obvious that bipedal movement allowed them to carry more of this precious resource, but also that they were actively trying to move as much as they could in one go by using everything available—even their mouths.
The second study, by Kimberley Hockings of Oxford Brookes University, was a 14- month study of Bossou chimpanzees crop-raiding, a situation in which they have to compete for rare and unpredictable resources. Here, 35 percent of the chimpanzees activity involved some sort of bipedal movement, and once again, this behavior appeared to be linked to a clear attempt to carry as much as possible at one time.

A:Because they imitated the human way of walking just for fun. B:Because they wanted to please the researchers to get more coula nuts from them. C:Because they wanted to get to die nut-rich forest faster by walking that way. D:Because they wanted to carry more nuts with two free limbs.

Most of us walk and carry items in our hands every day. These are seemingly simple activities that the majority of us don’t question. But an international team of researchers, including Dr. Richmond from GW’s Columbian College of Arts and Sciences, have discovered that human walking upright, may have originated millions of years ago as an adaptation to carrying scarce, high-quality resources. The team of researchers from the US, England, Japan and Portugal investigated the behavior of modern-day chimpanzees as they competed for food resources, in an effort to understand what ecological settings would lead a large ape—one that resembles the 6 million-year old ancestor we shared in common with living chimpanzees—to walk on two legs.
"These chimpanzees provide a model of the ecological conditions under which our earliest ancestors might have begun walking on two legs ", said Dr. Richmond.
The research findings suggest that chimpanzees switch to moving on two limbs instead of four in situations where they need to monopolize a resource. Standing on two legs allows them to carry much more at one time because it frees up their hands. Over time, intense bursts of bipedal activity may have led to anatomical changes that in turn became the subject of natural selection where competition for food or other resources was strong.
Two studies were conducted by the team in Guinea. The first study was conducted by the team in Kyoto University’s "outdoor laboratory" in a natural clearing in Bossou Forest. Researchers allowed the wild chimpanzees access to different combinations of two different types of nut—the oil palm nut, which is naturally widely available, and the coula nut, which is not. The chimpanzees’ behavior was monitored in three situations: (a) when only oil palm nuts were available, (b)when a small number of coula nuts were available, and(c) when coula nuts were the majority available resource.
When the rare coula nuts were available only in small numbers, the chimpanzees transported more at one time. Similarly, when coula nuts were the majority resource, the chimpanzees ignored the oil palm nuts altogether. The chimpanzees regarded the coula nuts as a more highly-prized resource and competed for them more intensely.
In such high-competition settings, the frequency of cases in which the chimpanzees started moving on two legs increased by a factor of four. Not only was it obvious that bipedal movement allowed them to carry more of this precious resource, but also that they were actively trying to move as much as they could in one go by using everything available—even their mouths.
The second study, by Kimberley Hockings of Oxford Brookes University, was a 14- month study of Bossou chimpanzees crop-raiding, a situation in which they have to compete for rare and unpredictable resources. Here, 35 percent of the chimpanzees activity involved some sort of bipedal movement, and once again, this behavior appeared to be linked to a clear attempt to carry as much as possible at one time.

A:Chimpanzees are in the same process of evolution as our ancestors were. B:Chimpanzees are similar to humans in many behaviors. C:Walking on two limbs and walking on four limbs each have their advantages. D:Human walking on two legs developed as a means of survival.

Regeneration of Limbs Most people would agree that it would be wonderful if humans could regenerate limbs. Those who have lost their arms or legs would be complete again. The day is still far off when this might happen. But in the last 10 years, doctors have reported regeneration in smaller parts of the body, most often fingers. Regeneration is not a newly-discovered process. For centuries, scientists have seen it work in some kinds of animals. Break off a lizards (蜥蜴的) tail, for example, and it will grow a new tail. Scientists now are looking for a way to turn on this exciting ability in more highly-developed animals, including humans. Their experiments show that nerves, cell chemistry and the natural electric currents in the body all seem to have a part in this process. The body of every animal contains general purpose cells that change into whatever kind of cells the body needs. Animals such as the lizard or salamander (蝾螈) use these cells to regenerate a new tail or leg when the old one is broken off. These cells collect around the wound. They form a mass called a blastema (胚基). The cells of the blastema begin to change. Some become bone cells, some muscle cells, some skin cells. Slowly, a new part re-grows from the body outward. When completed, the new part is just like the old one. More than 200 years ago, Italian scientist Luigi Spallanzani showed that younger animals have a greater ability to regenerate lost parts than older animals. So do animals lower on the ladder of evolutionary development. The major difference seems to be that less-developed animals have more nerves in their tails and legs than humans do in their arms and legs. Another helpful piece of information was discovered in the late 1800s. Scientists found that when a creature is injured, an electrical current flows around the wound. The strength of the current depends on how severe the wound is and on how much nerve tissue is present. In 1945, American scientist Meryl Rose tested another idea about regeneration. He thought a new limb might grow only from an open wound. Doctor Rose cut off the front legs of some frogs, below the knee. He kept the wounds wet with a strong salty liquid. This prevented skin from growing over the wounds. The results were surprising. Frogs do not regenerate new legs naturally. But these frogs began to grow new limbs. About half of each cut-off leg grew back again. New bones and muscles developed. This research has led doctors to new ways of treating cut-off fingers. Doctors have observed, for example, that many children and some adults will re-grow the top of a finger if the wound is left open. The passage indicates that______.

A:humans can never regenerate limbs B:human limbs may be regenerated on some animals first C:humans might be able to regenerate limbs in the future D:regeneration of human limbs will soon become a reality

Regeneration of Limbs
Most people would agree that it would be wonderful if humans could regenerate limbs. These who have lost their arms or legs would be complete again. The day is still far off when this might happen. But in the last 10 years, doctors have reported regeneration in smaller parts of the body, most often fingers.
Regeneration is not a newly-discovered process. For centuries, scientists have seen it work in some kinds of animals. Break off a lizard’s (蜥蜴的) tail, for example, and it will grow a new tail. Scientists now are looking for a way to turn on this exciting ability in more highly-developed animals, including humans. Their experiments show that nerves, cell chemistry and the natural electric currents in the body all seem to have a part in this process.
The body of every animal contains general purpose cells that change into whatever kind of cells the body needs. Animals such as the lizard or salamander (蝾螈) use these cells to regenerate a new tail or leg when the old one is broken off. These cells collect around the wound. They form a mass called a blastama (胚基). The cells of the blastema begin to change. Some become bone cells, some muscle cells, some skin cells. Slowly, a new part regrows from the body outward. When completed, the new part is just like the old one.
Mote than 200 years ago, Italian scientist Luigi Spallanzani showed that younger animals have a greater ability to regenerate lost parts than older animals. So do animals lower on the ladder of evolutionary development. The major difference seems to be that less-developed animals have more nerves in their tails and legs than humans do in their arms and legs.
Another helpful piece of information was discovered in the late 1600s. Scientists found that when a creature is injured, an electrical current flows around the wound. The strength of the current depends on how severe the wound is and on how much nerve tissue is present.
In 1945, American scientist Meryl Rose tested another idea about regeneration. He thought a new limb might grow only from an open wound. Doctor Rose cut off the front legs of some frogs, below the knee. He kept the wounds wet with a strong salty liquid. This prevented skin from growing over the wounds. The results were surprising. Frogs do not regenerate new legs naturally. But these frogs began to grow new limbs. About half of each cut-off leg grew back again. New bones and muscles developed.
This research has led doctors to new ways of treating cut-off fingers. Doctors have observed, for example, that many children and some adults will regrow the top of a finger if the wound is left open.

A:humans can never regenerate limbs. B:humans might be able to regenerate limbs in the future. C:human limbs may be regenerated on some animals first. D:regeneration of human limbs will soon become a reality.

The passage indicates that

A:humans can never regenerate limbs. B:humans might be able to regenerate limbs in the future. C:human limbs may be regenerated on some animals first. D:regeneration of human limbs will soon become a reality.

Regeneration of Limbs Most people would agree that it would be wonderful if humans could regenerate limbs. Those who have lost their arms or legs would be complete again. The day is still far off when this might happen. But in the last 10 years, doctors have reported regeneration in smaller parts of the body, most often fingers. Regeneration is not a newly-discovered process. For centuries, scientists have seen it work in some kinds of animals. Break off a lizards (蜥蜴的) tail, for example, and it will grow a new tail. Scientists now are looking for a way to turn on this exciting ability in more highly-developed animals, including humans. Their experiments show that nerves, cell chemistry and the natural electric currents in the body all seem to have a part in this process. The body of every animal contains general purpose cells that change into whatever kind of cells the body needs. Animals such as the lizard or salamander (蝾螈) use these cells to regenerate a new tail or leg when the old one is broken off. These cells collect around the wound. They form a mass called a blastema (胚基). The cells of the blastema begin to change. Some become bone cells, some muscle cells, some skin cells. Slowly, a new part re-grows from the body outward. When completed, the new part is just like the old one. More than 200 years ago, Italian scientist Luigi Spallanzani showed that younger animals have a greater ability to regenerate lost parts than older animals. So do animals lower on the ladder of evolutionary development. The major difference seems to be that less-developed animals have more nerves in their tails and legs than humans do in their arms and legs. Another helpful piece of information was discovered in the late 1800s. Scientists found that when a creature is injured, an electrical current flows around the wound. The strength of the current depends on how severe the wound is and on how much nerve tissue is present. In 1945, American scientist Meryl Rose tested another idea about regeneration. He thought a new limb might grow only from an open wound. Doctor Rose cut off the front legs of some frogs, below the knee. He kept the wounds wet with a strong salty liquid. This prevented skin from growing over the wounds. The results were surprising. Frogs do not regenerate new legs naturally. But these frogs began to grow new limbs. About half of each cut-off leg grew back again. New bones and muscles developed. This research has led doctors to new ways of treating cut-off fingers. Doctors have observed, for example, that many children and some adults will re-grow the top of a finger if the wound is left open. The passage indicates that______.

A:humans can never regenerate limbs B:human limbs may be regenerated on some animals first C:humans might be able to regenerate limbs in the future D:regeneration of human limbs will soon become a reality