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.

从解剖学上讲，现代人类大约在 30 万年前在非洲进化而来。早在 10 万年前，它们就开始出现在非洲以外的化石记录中，尽管其他古人类更早地存在于欧亚大陆。最近，几项研究基于全基因组序列分析支持现代人类的一次非洲外事件。然而，单一的非洲模式与化石记录中的一些发现形成对比，化石记录支持两个非洲事件，以及单亲数据，这表明回归非洲运动。在这里，我们使用深度学习方法与近似贝叶斯计算和顺序蒙特卡洛相结合，从全基因组序列的角度重新审视这些假设。我们的结果支持回归非洲模式而不是其他替代方案。我们估计，大约 60-9 万年前，非洲和非洲人口之间发生了两次连续的分离，相隔 13-15 千年。最近分裂产生的一个人口在很大程度上取代了西非老年人口，而另一个人口则建立了非洲以外的人口。