Friday, October 30, 2015

Northwestern Neolithic Anatolians were essentially "EEF" with less "WHG"

Well, it seems David wasn't wrong when he worked on the extremely low coverage genome of a farmer from Neolithic Northwestern Anatolia as we now have proof with far more samples from the recent Mathieson et al. 2015 to back up what he noticed.

What he noticed can be surmised via the PCA (Principal Component Analysis) / autosomal DNA based cluster above where the Barcin / Neolithic Northwestern Anatolian farmer whose genome he analyzed looked like she was essentially an Early European Farmer with less Western European Hunter-Gatherer-related ancestry.

As you can see in the PCA above where Mathieson et al. 2015's Anatolian Neolithic samples are present; they essentially cluster with Neolithic Europeans (F.e. Middle Neolithic) / Early European Farmers but pull farther away from Western European Hunter-Gatherers than they do.

This is all quite interesting as it suggests now that the Neolithic Farmers who entered Europe from West Asia (specifically Anatolia and into the Balkans) during Neolithic period already carried Western European Hunter-Gatherer-related ancestry.

These farmers who brought agriculture to Europe then stocked up on more WHG-related ancestry once they got to Europe (from mixing with the continent's local earlier forager inhabitants) resulting in individuals like the Stuttgart farmer who're more WHG-related in ancestry than these Anatolian Farmers from around 7,000 years ago.

Scope of Matheison et al.'s samples
The next step would obviously be acquiring more and more ancient DNA from West Asia. For now, it's difficult to assume all of Neolithic Anatolia was like these Barcin Farmers who lived so close to the Balkans & the Bosphoros (perhaps this explains their WHG-related ancestry visible outside of "ENF"?). 

It would be truly intriguing if Neolithic Anatolian farmers from areas such as Eastern or Central Anatolia also proved to be very EEF-like and not distinct from their Barcin Farmer neighbors.

However I suppose the old "EEF + ANE + WHG" model has been shaken up once again and Europeans are for now looking to basically be "Anatolian Neolithic-related + Yamnaya-related + WHG-related" on a as displayed above in charts from Mathieson et al. 2015.

With the Pontic Caspian Steppe side of Europeans being part Caucasian-like & part Eastern European Hunter-Gatherer-related which as this paper notes has a certain extra relation to Ancient North Eurasians like MA-1 that makes modeling Europeans as part "ANE" possible, and finally the Neolithic Farmers who came to Europe seemingly from Anatolia would've been part this component & part WHG-related.

The plot thickens with the more ancient DNA we get and there are still unanswered questions like the exact source of West Asian-related ancestry in Bronze Age Steppe Pastoralists like the Yamnaya & what exactly "Basal Eurasian" really could be. 

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