新视野大学英语读写教程听力 第四册 课文 te-07a_new
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[00:00.00]，就把hxen.com复制到QQ个人资料中！Research into Population Genetics
[00:-1.00]While not exactly a top selling book,
[00:-2.00]The History and Geography of Human Genes is a remarkable collection of
[00:-3.00]more than 50 years of research in population genetics.
[00:-4.00]It stands as the most extensive survey to date
[00:-5.00]on how humans vary at the level of their genes.
[00:-6.00]The book\'s firm conclusion;
[00:-7.00]once the genes for surface features such as skin color and height are discounted,
[00:-8.00]the "races" are remarkably alike under the skin.
[00:-9.00]The variation among individuals is much greater than the differences among groups.
[00:10.00]In fact,there is no scientific basis for theories
[00:11.00]pushing the genetic superiority of any one population over another.
[00:12.00]The book,however,
[00:13.00]is much more than an argument against the latest racially biased theory.
[00:14.00]The prime mover behind the project,Luca Cavalli-Sforza,
[00:15.00]a Stanford professor,labored with his colleagues for 16 years
[00:16.00]to create nothing less than the first genetic map of the world.
[00:17.00]The book features more than 500 maps that show areas of genetic similarity
[00:18.00]— much as places of equal altitude are shown by the same color on other maps.
[00:19.00]By measuring how closely current populations are related,
[00:20.00]the authors trace the routes by which early humans migrated around the earth.
[00:21.00]Result:the closest thing we have to a global family tree.
[00:22.00]The information needed to draw that tree is found in human blood:
[00:23.00]various proteins that serve as markers to reveal a person\'s genetic makeup.
[00:24.00]Using data collected by scientists over decades,
[00:25.00]the authors assembled profiles of hundreds of thousands of individuals
[00:26.00]from almost 2,000 groups.
[00:27.00]And to ensure the populations were "pure",
[00:28.00]the study was confined to groups that were in their present locations as of 1492,
[00:29.00]before the first major movements from Europe began
[00:30.00]—in effect,a genetic photo of the world when Columbus sailed for America.
[00:31.00]Collecting blood,particularly from ancient populations in remote areas,
[00:32.00]was not always easy;
[00:33.00]potential donors were often afraid to cooperate,
[00:34.00]or raised religious concerns.
[00:35.00]On one occasion,when Cavalli-Sforza was taking blood samples
[00:36.00]from children in a rural region of Africa,
[00:37.00]he was confronted by an angry farmer waving an axe.
[00:38.00]Recalls the scientist:"I remember him saying, ’
[00:39.00]If you take the blood of the children, I\'ll take yours.’
[00:40.00]He was worried that we might want to do some magic with the blood."
[00:41.00]Despite the difficulties, the scientists made some remarkable discoveries.
[00:42.00]One of them jumps right off the book\'s cover:
[00:43.00]a color map of the world\'s genetic variation
[00:44.00]has Africa at one end of the range and Australia at the other.
[00:45.00]Because Australia\'s native people and black Africans
[00:46.00]share such superficial characteristics as skin color and body shape,
[00:47.00]they were widely assumed to be closely related.
[00:48.00]But their genes tell a different story.
[00:49.00]Of all humans,Australians are most distant from the Africans
[00:50.00]and most closely resemble their neighbors,the Southeast Asians.
[00:51.00]What the eye sees as racial differences
[00:52.00]—between Europeans and Africans,for example
[00:53.00]—are mainly a way to adapt to climate as humans move from one continent to another.
[00:54.00]The same map,in combination with ancient human bones,
[00:55.00]confirms that Africa was the birthplace of humanity
[00:56.00]and thus the starting point of the original human movements.
[00:57.00]Those findings,
[00:58.00]plus the great genetic distance between present-day Africans and non-Africans,
[00:59.00]indicate that the split from the African branch
[-1:00.00]is the oldest on the human family tree.
[-1:-1.00]The genetic maps also shed new light on the origins of populations
[-1:-2.00]that have long puzzled scientists.Example:
[-1:-3.00]the Khoisan people of southern Africa.
[-1:-4.00]Many scientists consider the Khoisan a distinct race of very ancient origin.
[-1:-5.00]The unique character of the clicking sounds in their language
[-1:-6.00]has persuaded some researchers
[-1:-7.00]that the Khoisan people are directly descended from the most primitive human ancestors.
[-1:-8.00]But their genes beg to differ.
[-1:-9.00]They show that the Khoisan may be a very ancient mix of west Asians and black Africans.
[-1:10.00]A genetic trail visible on the maps shows that the breeding ground
[-1:11.00]for this mixed population probably lies in Ethiopia or the Middle East.
[-1:12.00]The most distinctive members of the European branch of the human tree
[-1:13.00]are the Basques of France and Spain.
[-1:14.00]They show unusual patterns for several genes,
[-1:15.00]including the highest rate of a rare blood type.
[-1:16.00]Their language is of unknown origin
[-1:17.00]and cannot be placed within any standard classification.
[-1:18.00]And the fact that they live in a region next to famous caves
[-1:19.00]which contain vivid paintings from Europe\'s early humans,
[-1:20.00]leads Cavalli-Sforza to the following conclusion:
[-1:21.00]"The Basques are extremely likely to be the most direct relatives
[-1:22.00]of the Cro-Magnon people,
[-1:23.00]among the first modern humans in Europe."
[-1:24.00] All Europeans are thought to be a mixed population,
[-1:25.00]with 65% Asian and 35% African genes.
[-1:26.00]In addition to telling us about our origins,
[-1:27.00]genetic information is also the latest raw material of the medical industry,
[-1:28.00]which hopes to use human DNA to build specialized proteins
[-1:29.00]that may have some value as disease-fighting drugs.
[-1:30.00]Activists for native populations
[-1:31.00]fear that the scientists could exploit these peoples:
[-1:32.00]genetic material taken from blood samples
[-1:33.00]could be used for commercial purposes without adequate payment
[-1:34.00]made to the groups that provide the DNA.
[-1:35.00]Cavalli-Sforza stresses that his mission
[-1:36.00]is not just scientific but social as well.
[-1:37.00]The study\'s ultimate aim,he says,
[-1:38.00]is to"weaken conventional notions of race"that cause racial prejudice.
[-1:39.00]It is a goal that he hopes will be welcomed among native peoples
[-1:40.00]who have long struggled for the same end.
新视野大学英语第四册 新视野大学英语 新视野大学英语3 新视野大学英语2 新视野大学英语四 新视野大学英语第三版第四册 新视野大学英语第二版第四册 第三版新视野
[00:00.00]，就把hxen.com复制到QQ个人资料中！Research into Population Genetics
[00:-1.00]While not exactly a top selling book,
[00:-2.00]The History and Geography of Human Genes is a remarkable collection of
[00:-3.00]more than 50 years of research in population genetics.
[00:-4.00]It stands as the most extensive survey to date
[00:-5.00]on how humans vary at the level of their genes.
[00:-6.00]The book\'s firm conclusion;
[00:-7.00]once the genes for surface features such as skin color and height are discounted,
[00:-8.00]the "races" are remarkably alike under the skin.
[00:-9.00]The variation among individuals is much greater than the differences among groups.
[00:10.00]In fact,there is no scientific basis for theories
[00:11.00]pushing the genetic superiority of any one population over another.
[00:12.00]The book,however,
[00:13.00]is much more than an argument against the latest racially biased theory.
[00:14.00]The prime mover behind the project,Luca Cavalli-Sforza,
[00:15.00]a Stanford professor,labored with his colleagues for 16 years
[00:16.00]to create nothing less than the first genetic map of the world.
[00:17.00]The book features more than 500 maps that show areas of genetic similarity
[00:18.00]— much as places of equal altitude are shown by the same color on other maps.
[00:19.00]By measuring how closely current populations are related,
[00:20.00]the authors trace the routes by which early humans migrated around the earth.
[00:21.00]Result:the closest thing we have to a global family tree.
[00:22.00]The information needed to draw that tree is found in human blood:
[00:23.00]various proteins that serve as markers to reveal a person\'s genetic makeup.
[00:24.00]Using data collected by scientists over decades,
[00:25.00]the authors assembled profiles of hundreds of thousands of individuals
[00:26.00]from almost 2,000 groups.
[00:27.00]And to ensure the populations were "pure",
[00:28.00]the study was confined to groups that were in their present locations as of 1492,
[00:29.00]before the first major movements from Europe began
[00:30.00]—in effect,a genetic photo of the world when Columbus sailed for America.
[00:31.00]Collecting blood,particularly from ancient populations in remote areas,
[00:32.00]was not always easy;
[00:33.00]potential donors were often afraid to cooperate,
[00:34.00]or raised religious concerns.
[00:35.00]On one occasion,when Cavalli-Sforza was taking blood samples
[00:36.00]from children in a rural region of Africa,
[00:37.00]he was confronted by an angry farmer waving an axe.
[00:38.00]Recalls the scientist:"I remember him saying, ’
[00:39.00]If you take the blood of the children, I\'ll take yours.’
[00:40.00]He was worried that we might want to do some magic with the blood."
[00:41.00]Despite the difficulties, the scientists made some remarkable discoveries.
[00:42.00]One of them jumps right off the book\'s cover:
[00:43.00]a color map of the world\'s genetic variation
[00:44.00]has Africa at one end of the range and Australia at the other.
[00:45.00]Because Australia\'s native people and black Africans
[00:46.00]share such superficial characteristics as skin color and body shape,
[00:47.00]they were widely assumed to be closely related.
[00:48.00]But their genes tell a different story.
[00:49.00]Of all humans,Australians are most distant from the Africans
[00:50.00]and most closely resemble their neighbors,the Southeast Asians.
[00:51.00]What the eye sees as racial differences
[00:52.00]—between Europeans and Africans,for example
[00:53.00]—are mainly a way to adapt to climate as humans move from one continent to another.
[00:54.00]The same map,in combination with ancient human bones,
[00:55.00]confirms that Africa was the birthplace of humanity
[00:56.00]and thus the starting point of the original human movements.
[00:57.00]Those findings,
[00:58.00]plus the great genetic distance between present-day Africans and non-Africans,
[00:59.00]indicate that the split from the African branch
[-1:00.00]is the oldest on the human family tree.
[-1:-1.00]The genetic maps also shed new light on the origins of populations
[-1:-2.00]that have long puzzled scientists.Example:
[-1:-3.00]the Khoisan people of southern Africa.
[-1:-4.00]Many scientists consider the Khoisan a distinct race of very ancient origin.
[-1:-5.00]The unique character of the clicking sounds in their language
[-1:-6.00]has persuaded some researchers
[-1:-7.00]that the Khoisan people are directly descended from the most primitive human ancestors.
[-1:-8.00]But their genes beg to differ.
[-1:-9.00]They show that the Khoisan may be a very ancient mix of west Asians and black Africans.
[-1:10.00]A genetic trail visible on the maps shows that the breeding ground
[-1:11.00]for this mixed population probably lies in Ethiopia or the Middle East.
[-1:12.00]The most distinctive members of the European branch of the human tree
[-1:13.00]are the Basques of France and Spain.
[-1:14.00]They show unusual patterns for several genes,
[-1:15.00]including the highest rate of a rare blood type.
[-1:16.00]Their language is of unknown origin
[-1:17.00]and cannot be placed within any standard classification.
[-1:18.00]And the fact that they live in a region next to famous caves
[-1:19.00]which contain vivid paintings from Europe\'s early humans,
[-1:20.00]leads Cavalli-Sforza to the following conclusion:
[-1:21.00]"The Basques are extremely likely to be the most direct relatives
[-1:22.00]of the Cro-Magnon people,
[-1:23.00]among the first modern humans in Europe."
[-1:24.00] All Europeans are thought to be a mixed population,
[-1:25.00]with 65% Asian and 35% African genes.
[-1:26.00]In addition to telling us about our origins,
[-1:27.00]genetic information is also the latest raw material of the medical industry,
[-1:28.00]which hopes to use human DNA to build specialized proteins
[-1:29.00]that may have some value as disease-fighting drugs.
[-1:30.00]Activists for native populations
[-1:31.00]fear that the scientists could exploit these peoples:
[-1:32.00]genetic material taken from blood samples
[-1:33.00]could be used for commercial purposes without adequate payment
[-1:34.00]made to the groups that provide the DNA.
[-1:35.00]Cavalli-Sforza stresses that his mission
[-1:36.00]is not just scientific but social as well.
[-1:37.00]The study\'s ultimate aim,he says,
[-1:38.00]is to"weaken conventional notions of race"that cause racial prejudice.
[-1:39.00]It is a goal that he hopes will be welcomed among native peoples
[-1:40.00]who have long struggled for the same end.
新视野大学英语第四册 新视野大学英语 新视野大学英语3 新视野大学英语2 新视野大学英语四 新视野大学英语第三版第四册 新视野大学英语第二版第四册 第三版新视野
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