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科学美国人60秒:DNA显示人类多次向美洲迁移

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E;~v1TJD!Y^ZxG&V~2jb&@yQw,|y!f=2aThis is Scientific American — 60-Second Science. I'm Emily Schwing.
For more than ten thousand years, Alaska Native and Canadian First Nations people have lived along the Northwest coast of North America. Now, ancient remains have provided genetic proof of that long habitation.
"There's largely the same gene pool in northern northwest North America today that there was ten thousand years ago."
Ripan Malhi at the University of Illinois–Champaign. He and colleagues analyzed the DNA in four skeletons found in the region that range from 1,500 to 10,000 years old. And the results have two major implications. First, they support traditional oral histories about life in the region. Second, they open up the possibility for new theories about how people migrated to the continent—namely, more than one colonization.
"It could be that folks first moved south into Central and South America and then back up into North America, or it could be that there was another movement from northeast Asia into North America later on in time. So, there are many different possibilities that could explain the patterns that we are seeing."
The study is in the Proceedings of the National Academy of Sciences.
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The researchers also compared genetic data from Northwest coast populations with DNA in remains unearthed south of the Canadian border. The analysis shows that the almost 13,000 year old Anzick Child found in Montana is related more closely to people from Central and South America than to Washington state's 9,000-year-old Kennewick Man, who is of entirely different lineage. He is not related to people of the Northwest Coast, and his genes aren't all that closely linked to Anzick Child's South American relatives either. Which shows that the story of the settlement of the Western Hemisphere is still very much a work in progress.
Thanks for listening the Scientific American — 60-Second Science Science. I'm Emily Schwing.
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original [ə'ridʒənl]
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adj. 最初的,原始的,有独创性的,原版的
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gene [dʒi:n]
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n. 基因
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related [ri'leitid]
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adj. 相关的,有亲属关系的
 
movement ['mu:vmənt]
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n. 活动,运动,移动,[音]乐章
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genetic [dʒi'netik]
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adj. 基因的,遗传的,起源的
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collapse [kə'læps]
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n. 崩溃,倒塌,暴跌
v. 倒塌,崩溃,瓦解
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range [reindʒ]
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n. 范围,行列,射程,山脉,一系列
v. 排
 
colonization [,kɔlənai'zeiʃən]
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n. 殖民;殖民地化
 
hemisphere ['hemisfiə]
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n. 半球
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construction [kən'strʌkʃən]
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n. 建设,建造,结构,构造,建筑物
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