基因化石如是说

一个多世纪以来，古人类学家在现代人的起源问题上一直争论不休。

目前很多科学家支持“非洲起源说”，还有少数科学家则支持“多地区进化说”。你知道这其中的秘密吗？你又会支持哪一派的观点呢？下面这篇文章将带我们一起去探寻人类的起源。

Scientists have long held that modern humans originated in Africa because that’s where they’ve found the oldest bones. Geneticists¹ have come to the same conclusion by looking at Africa’s vast genetic diversity, which could only have arisen as DNA mutated² over millennia. There’s less consensus about the routes our ancestors took in their journey out of Africa and around the planet. Early migrations stalled but left behind evidence such as a human skullfrom 92 000 years ago in Israel. Those people may have taken a northern route through the Nile Valley into the Middle East. But other emigrants who left Africa tens of thousands of years later could also have taken a different route: across the southern end of the Red Sea. Scientists say these more recent wanderers gave rise to the 5.5 billion humans living outside Africa today.”I think the broad human prehistoric framework is in place,”says geneticist Peter Forster of the McDonald Institute for Archaeological Research in Cambridge, England, ”and we’re now fitting in the details.”

很长时间以来，科学家都认为现代人类应该起源于非洲，因为他们在那里发现了最早的尸骨。遗传学者也留意到了非洲起源的巨大差异，正是这种差异引发了上千年的DNA变异，因此，他们也做出了同样的结论。至于我们的祖先所经历的历程到底是不是在非洲之外或是这个星球的其他地方，还没有达成一致的结论。早期的移民保存了一些证据，但是免不了还是遗漏了一些，比如说在以色列发现的92 000年以前的人类的头骨。据推测，那些人应该是顺着尼罗河谷北上最后进入中东地区。但是几万年之后那些离开非洲迁往其他地方的人们也许又会经历不同的历程：穿过最南端到达红海。科学家们说，这些最近的“漂移者”已经接近55亿，他们如今已不在非洲生活了。“我想，这个‘人类史前框架’已经基本形成，”英国剑桥“麦克唐纳考古研究机构”的遗传学者彼得·福斯特说，“现在，我们正在着手其中具体的细节研究。”

伊织摘译自Discover

１. geneticist [d3I"5netIsIst] n. 遗传学者２. mutate [mju:"teIt] v. 变异

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