开云平台：科学家发现尼安德特人携带人类DNA

In 1997，scientists found the first scrap of neanderthal DNA in a fossil . since then，they have recovered genetic material，even enent From1997年，科学家首次在化石中发现尼安德特人DNA的碎片。此后，他们从接二连三发掘出的各种尼安德特人的骨骼中提取出基因物质，甚至原始基因组。

他们的研究进入了难以置信的发现。今天，除了非洲人以外，人类1%到2%的DNA都来自尼安德特人。

that genetic legacy is the result of interbreeding roughly 50，000 years ago between Neanderthals and the common ancestors of Europeans and asiaans这种基因遗产是大约5万年前尼安德特人和欧亚人的联合祖先交配的结果。最近的研究表明，尼安德特人的基因也会影响今天的人体健康，与包括过敏和抑郁症在内的各种症状有关。

now scientists have found that the genes flowed both ways . in A study published on Wednesday in nature，A team of scientists reports that another in如今，科学家们发现基因的流动是双向的。《大自然》杂志(Nature)周三发表的一篇研究论文中，一位科学家提交的案例显示，杂交品种导致西伯利亚的尼安德特人拥有部分人类DNA。This exchange，the scientists conclude，took place about 100，000 years ago . that ' s a puzzling date，Because a great deal of evidence因为有很多证据表明，在50，000至60，000年前还没有从非洲出来的人类祖先进入了非洲大陆。

It's possible，then，that these neander thal s acquired DNA from A mysterious early migration of humans " I think at this point we ' ve“but the story behind the observation is still very much in din我指出，我们已经让所有人相信我们的观测是现实的。”Cold Spring Harbor实验室的遗传学家亚当西佩尔回答说。

“美国冷泉港研究所的遗传学家亚当西佩尔回答说。他是这项新研究的共同作者。”但是观测结果后面的说明仍然存在争议。“Humans and neanderthal s split from a common ancestor in Africa about 600，000 years ago . at some point afterward，The ancestors of neanderthal大约60万年前，享有非洲联盟祖先的人类和尼安德特人分道扬镳。

之后的某一瞬间，尼安德特人的祖先传播到欧洲、中东和中亚。Along the way，neander thal s took on a distinctive anatomy-a stocky，Powerful build-and became impressive hunters of big game . the在迁移过程中，最后一代尼安德特人可能在大约4万年前灭亡。In 2010，scientists at The Max Planck Institute for Evolutionary Anthropology in Leipzig，Germany，Recovered about 60 percent of a neapzig科学家发现，尼安德特人和今天的欧亚人共享某些基因突变，但与现代非洲人没有共同之处。

科学家们得出结论，人类离开非洲大陆后，肯定与尼安德特人进行了杂交。Three years later，the max Planck team reconstructed the complete genome of a male neanderthal from a toe bone dating back at least 50，000 yeast wheast通过阿尔泰山脉尼安德特人的基因组和现代人类的DNA证明了杂交物种的存在。Recently，the researchers harvested more DNA from European neanderthal fossils，putting together very detailed reconstructions of a sins最近，研究人员从欧洲尼安德特人化石收集到更好的DNA信息，重组了非常详细的单染色体3354号染色体。

Sergi castellano，a geneticist at max Planck institute，Set out to compare this European neanderthal DNA to the genes from Siberia . he was cus马克斯普朗克研究所的遗传学家谢尔盖卡斯特利亚诺(Sergi Castellano)将欧洲尼安德特人的DNA与西伯利亚尼安德特人进行了比较，他感兴趣的是尼安德特人群体相互隔绝的程度以及与当今人类的联系。He was joined by Dr. Siepel，Who has developed powerful statistical models in recent years to trace how DNA changes over time . he and his colleages在过去的几年里，Siper建立了一个强大的统计模型，用于追踪DNA是如何随着时间演化的。因此，他和他的同事应该比较这些基因组，推测他们的联合历史。例如，要猜测他们的祖先是如何分化的，祖先的人口规模有多大。

(大卫亚设，Northern Exposure(美国电视电视剧)，家)Dr. Siepel，dr . castellano and their colleagues used these models to analyze the numberSiper、Kasteliano和同事们利用这些模型分析了尼安德特人和人类的DNA。他们的分析结果证明，以前的研究表明，尼安德特人的DNA片段经常出现在现代欧亚人身上。

But they also found another example of so-called gene flow，And an un expected one at that 3360 the Altai neander thals in particular shared some me但是他们也找到了“基因流动”的另一个例子，特别是阿尔泰山脉的尼安德特人和今天的非洲人之间有一定的变异。that pattern suggests that an African lineage of humans interbred with the ancestors of the Altai neander thal after they split from other neander thasdr . castellano and dr . siepel thought at first there was something wrong with their analysis，So they went back to fix it。but when they looked for the problem，they could not find it。

卡斯特利亚诺和西佩尔最初认为自己的分析是错误的，所以去修改了。但是他们没有找到问题。“we poked and prodded and poked and prodded，and couldn't get it to go away，said dr . siepel Once the scientists accepted that the inneing”DNA不会在代间油田开始重组，可以用于日程安排。Based on this gene shuffling，the scientists estimated that humans and the ancestors ofthe Altai neander thals interbred about 100，000 years ago-long before people were thought to have left Africa。

“this observation throws a wrench in the works，”saiddr.sid科学家推测，人类和阿尔泰山脉尼安德特人的祖先大约10万年前开始杂交。这一观测给我们的工作带来了相当大的困难。

“西佩尔说。Bence viola，a pale ontologist at the university of Toronto and a co-author of the new study，Said he was skeptical when he first learned of theit's really weird，that's my main impression，“he said。当他和这位新的研究作者多伦多大学(University of Toronto)古生物学家文斯维奥拉一起听到这个基因数据的消息时，他自己充满了怀疑。感觉很奇怪那是我的主要印象。

”他说。Eventually，however，dr . castellano persuaded him the data were strong，and dr . viola looked over the fossil record for possil所以上蹿下跳In the 1930s，for example，scientists discovered 120，000-year-old fossils in Israel that looked a lot like living humans . mans例如，20世纪30年代，科学家在以色列发现了12万年前的化石，与现代人类有很多相似之处。

许多科学家指出，这代表着人类进入非洲的一次最终尝试，表明今天人类和基因没有联系。(威廉莎士比亚、奥赛罗、科学)In October，Chinese researchers discovered another intriguing clue In a cave 3360 47 teeth that they estimate are betwetwerthe scientists argue that the teeth belonged to modern humans。今年10月，中国研究人员在一个山洞里发现了另一个有趣的线索：47颗牙齿。

这些科学家推测牙齿的历史是8万到12万年，明确提出它们属于现代人类。dr . viola is not completely convinced by the Chinese study . instead，He thinks the scenario that best fits the evidence is that humans expanding中国科学家的研究几乎没有说服中提琴。他指出，符合证据的最坏情况是，在中东蔓延的人类与当地尼安德特人进行了杂交。

然后尼安德特人带着人类的DNA向东迁移到西伯利亚地区。“it seems pretty solid，”said Jonathan K. Pritchard，a geneticist at Stanford university who was not involved in the study。“The story they ' re telling is pretty coherent。

”看起来很有说服力“没有参与这项研究的斯坦福大学遗传学家乔纳森K .普里查德(Jonathan K. Pritchard)”总的来说，他们明确提出的这句话比较有条理。“dr . Pritchard said that more examinations of ancient DNA would help resolve the many questions raised by the new study and help scientists undered by the new study and help scientistsI would expect in the next few years we ' ll have much，much more And it will be possible to piece this all together。“很快很多新数据就不会经常出现了，”他说。“指出在未来几年里，很少的碎片不会出来，还可以把它们收集在一起。

(太棒了)。

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