Institute of Genomics, University of Tartu, Tartu 51010, Estonia; Department of Biology-Genetics, University of Bari, Bari 70124, Italy.
Institute of Genomics, University of Tartu, Tartu 51010, Estonia.
Am J Hum Genet. 2021 Nov 4;108(11):2037-2051. doi: 10.1016/j.ajhg.2021.09.006. Epub 2021 Oct 8.
Anatomically modern humans evolved around 300 thousand years ago in Africa. They started to appear in the fossil record outside of Africa as early as 100 thousand years ago, although other hominins existed throughout Eurasia much earlier. Recently, several studies argued in favor of a single out of Africa event for modern humans on the basis of whole-genome sequence analyses. However, the single out of Africa model is in contrast with some of the findings from fossil records, which support two out of Africa events, and uniparental data, which propose a back to Africa movement. Here, we used a deep-learning approach coupled with approximate Bayesian computation and sequential Monte Carlo to revisit these hypotheses from the whole-genome sequence perspective. Our results support the back to Africa model over other alternatives. We estimated that there are two sequential separations between Africa and out of African populations happening around 60-90 thousand years ago and separated by 13-15 thousand years. One of the populations resulting from the more recent split has replaced the older West African population to a large extent, while the other one has founded the out of Africa populations.
解剖学上的现代人类大约在 30 万年前在非洲进化而来。早在 10 万年前，他们就开始出现在非洲以外的化石记录中，尽管更早的时候欧亚大陆上就存在其他原始人类。最近，几项研究基于全基因组序列分析，支持现代人类起源于非洲的单一事件。然而，这种单一的非洲起源模型与一些化石记录的发现相矛盾，这些发现支持现代人类有两次从非洲走出的事件，以及单倍体数据提出的返回非洲的运动。在这里，我们使用深度学习方法结合近似贝叶斯计算和序列蒙特卡罗方法，从全基因组序列的角度重新审视这些假说。我们的研究结果支持返回非洲模型，而不是其他替代模型。我们估计，在 6 万到 9 万年前，非洲和非洲以外的人群之间发生了两次连续的分离，其间相隔 1.3 万到 1.5 万年。最近一次分离产生的一个群体在很大程度上取代了较老的西非群体，而另一个群体则建立了非洲以外的人群。
