Patterson Nick, Richter Daniel J, Gnerre Sante, Lander Eric S, Reich David
Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA.
Nature. 2006 Jun 29;441(7097):1103-8. doi: 10.1038/nature04789. Epub 2006 May 17.
The genetic divergence time between two species varies substantially across the genome, conveying important information about the timing and process of speciation. Here we develop a framework for studying this variation and apply it to about 20 million base pairs of aligned sequence from humans, chimpanzees, gorillas and more distantly related primates. Human-chimpanzee genetic divergence varies from less than 84% to more than 147% of the average, a range of more than 4 million years. Our analysis also shows that human-chimpanzee speciation occurred less than 6.3 million years ago and probably more recently, conflicting with some interpretations of ancient fossils. Most strikingly, chromosome X shows an extremely young genetic divergence time, close to the genome minimum along nearly its entire length. These unexpected features would be explained if the human and chimpanzee lineages initially diverged, then later exchanged genes before separating permanently.
两个物种之间的遗传分化时间在整个基因组中差异很大，这传达了有关物种形成时间和过程的重要信息。在此，我们开发了一个研究这种变异的框架，并将其应用于来自人类、黑猩猩、大猩猩及亲缘关系更远的灵长类动物的约2000万个碱基对的比对序列。人类与黑猩猩的遗传分化在平均值的不到84%至超过147%之间变化，范围超过400万年。我们的分析还表明，人类与黑猩猩的物种形成发生在不到630万年前，可能更近，这与对古代化石的一些解释相冲突。最引人注目的是，X染色体显示出极其年轻的遗传分化时间，几乎在其整个长度上都接近基因组最小值。如果人类和黑猩猩谱系最初分化，然后在永久分离之前进行了基因交换，那么这些意外特征就可以得到解释。
