Pan-African metapopulation model explains Homo sapiens genetic and morphological evolution

Abstract

Emerging evidence has challenged the traditional view of a single-region origin for Homo sapiens, suggesting instead that our species arose and diversified across multiple geographically distinct populations in Africa, which intermittently exchanged genes and culture. However, our understanding of how this Pan-African metapopulation would have changed through time is still limited. Further, the drivers of such changes are uncertain, and quantitative models of the respective contribution of different African regions are lacking. Here we provide a complete reconstruction of the meta-population dynamics over the last 200,000 years by quantitatively integrating an environmental niche model based on archaeological sites within a spatially explicit population genetic framework. The inferred metapopulation dynamics not only fully explains the divergence among all available contemporary and ancient genomes of African hunter-gatherers, which were used to calibrate the model, but also accurately predicts the patterns of craniometric diversification across the continent from the Middle Pleistocene to the present. Furthermore, we show how the climate-driven changes in population sizes and connectivity predict major patterns of archaeological and phenotypic diversification over the last 200,000 years across the African continent.