Research press release


Nature Ecology & Evolution

Neanderthal–early human interbreeding assessed



Fernando VillaneaとJoshua Schraiberは、現生人類ゲノムの大規模なデータセットにおいて、東アジア系の人々とヨーロッパ系の人々の、ネアンデルタール人由来DNAのパターンに見られる非対称性を分析した。そして、異なる回数の交雑事象に関して解剖学的現生人類のゲノムに対するネアンデルタール人DNAの寄与をシミュレーションし、これらのパラメーターの多い複雑なモデルを機械学習の手法を用いて検討した。その結果、現生人類ゲノムに見られたネアンデルタール人由来DNAのパターンは、ネアンデルタール人集団と、東アジア人集団とヨーロッパ人集団の両方との間の複数回の交雑事象によって最もよく説明される、と結論付けられた。


Neanderthals and ancestors of anatomically modern humans did interbreed at multiple points in time, according to the large-scale genetic analyses of Neanderthal DNA fragments in contemporary East Asians and Europeans published this week in Nature Ecology & Evolution.

When anatomically modern humans dispersed from Africa, they encountered Neanderthals in western Eurasia. These encounters left a signature in the genomes of contemporary non-African populations: about 2% of their genomes include a Neanderthal component. Initially, it was assumed that only a single episode of interbreeding between modern humans and Neanderthals occurred, but the observation that the proportion of Neanderthal ancestry is 12-20% higher in East Asian individuals relative to Europeans suggested the possibility of multiple encounters.

Fernando Villanea and Joshua Schraiber analysed the asymmetry in the patterns of DNA of Neanderthal origin between individuals of East Asian and European ancestry in a large dataset of modern human genomes. The authors then simulated contributions of Neanderthal DNA to the genomes of anatomically modern humans for different numbers of interbreeding events and used a machine learning approach to explore these complex models with many parameters. They conclude that the observed patterns of DNA of Neanderthal origin in modern human genomes are best explained by not one but multiple episodes of interbreeding between Neanderthal and both East Asian and European populations.

The authors conclude that multiple episodes of modern human–Neanderthal encounters fit with the emerging view of complex and frequent interactions between different hominin groups.

doi: 10.1038/s41559-018-0735-8


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