Sunday, December 6, 2020

The Genetics Of The First Farmers Of Europe

Analysis of 15 ancient DNA samples from Western Anatolia and Southern Germany suggests that the first farmers of Europe had less European hunter-gatherer introgression than previously believed and were only a sister population to the first Central Anatolian farmers.
While the Neolithic expansion in Europe is well described archaeologically, the genetic origins of European first farmers and their affinities with local hunter-gatherers (HGs) remain unclear. 
To infer the demographic history of these populations, the genomes of 15 ancient individuals located between Western Anatolia and Southern Germany were sequenced to high quality, allowing us to perform population genomics analyses formerly restricted to modern genomes. 
We find that all European and Anatolian early farmers descend from the merging of a European and a Near Eastern group of HGs, possibly in the Near East, shortly after the Last Glacial Maximum (LGM). 
Western and Southeastern European HG are shown to split during the LGM, and share signals of a very strong LGM bottleneck that drastically reduced their genetic diversity. 
Early Neolithic Central Anatolians seem only indirectly related to ancestors of European farmers, who probably originated in the Near East and dispersed later on from the Aegean along the Danubian corridor following a stepwise demic process with only limited (2-6%) but additive input from local HGs.

Our analyses provide a time frame and resolve the genetic origins of early European farmers. They highlight the impact of Late Pleistocene climatic fluctuations that caused the fragmentation, merging and reexpansion of human populations in SW Asia and Europe, and eventually led to the world's first agricultural populations.
Nina Marchi, et al., "The mixed genetic origin of the first farmers of Europe" bioRxiv (November 23, 2020) doi:

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