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суббота, 22 сентября 2018 г.

Early Anatolian farmers were overwhelmingly of local hunter-gatherer origin (Feldman et...

Over at bioRxiv at this LINK. The dataset in this preprint includes just one Anatolian hunter-gatherer, but that’s enough to make the point that in Anatolia, unlike in Europe, there was very strong genetic continuity between the local foragers and earliest farmers. His Y-chromosome haplogroup is an interesting one: C1a2, which has been recorded in European remains from the Upper Paleolithic. Below is the abstract and a pertinent quote. I think this preprint basically confirms what I argued about the origin of the so called Villabruna hunter-gatherer clade back in 2016 (see here). Emphasis is mine.



Anatolia was home to some of the earliest farming communities. It has been long debated whether a migration of farming groups introduced agriculture to central Anatolia. Here, we report the first genome-wide data from a 15,000 year-old Anatolian hunter-gatherer and from seven Anatolian and Levantine early farmers. We find high genetic continuity between the hunter-gatherer and early farmers of Anatolia and detect two distinct incoming ancestries: an early Iranian/Caucasus related one and a later one linked to the ancient Levant. Finally, we observe a genetic link between southern Europe and the Near East predating 15,000 years ago that extends to central Europe during the post-last-glacial maximum period. Our results suggest a limited role of human migration in the emergence of agriculture in central Anatolia.

Among the Later European HG, recently reported Mesolithic hunter-gatherers from the Balkan peninsula, which geographically connects Anatolia and central Europe (‘Iron Gates HG’) [18], are genetically closer to AHG when compared to all the other European hunter-gatherers, as shown in the significantly positive statistic D(Iron_Gates_HG, European hunter-gatherers; AHG, Mbuti/Altai). Iron Gates HG are followed by Epigravettian and Mesolithic individuals from Italy and France (Villabruna [14] and Ranchot88 respectively [17]) as the next two European hunter-gatherers genetically closest to AHG [20] (Fig. 3A and data table S5). Iron Gates HG have been suggested to be genetically intermediate between WHG and eastern European hunter-gatherers (EHG) with an additional unknown ancestral component [18]. We find that Iron Gates HG can be modeled as a three-way mixture of Near-Eastern hunter-gatherers (25.8 ± 5.0 % AHG or 11.1 ± 2.2 % Natufian), WHG (62.9 ± 7.4 % or 78.0 ± 4.6 % respectively) and EHG (11.3 ± 3.3 % or 10.9 ± 3 % respectively); (tables S4 and S9). The affinity detected by the above D-statistic can be explained by gene flow from Near-Eastern hunter-gatherers into the ancestors of Iron Gates or by a gene flow from a population ancestral to Iron Gates into the Near-Eastern hunter-gatherers as well as by a combination of both. To distinguish the direction of the gene flow, we examined the Basal Eurasian ancestry component (α), which is prevalent in the Near East [6] but undetectable in European hunter-gatherers [17]. Following a published approach [6], we estimated α to be 24.8 ± 5.5 % in AHG and 38.5 ± 5.0 % in Natufians (Fig. 3B, table S10), consistent with previous estimates for the latter [6]. Under the model of unidirectional gene flow from Anatolia to Europe, 6.4 % is expected for α of Iron Gates by calculating (% AHG in Iron Gates HG) × (α in AHG). However, Iron Gates can be modeled without any Basal Eurasian ancestry or with a non-significant proportion of 1.6 ± 2.8 % (Fig. 3B, table S10), suggesting that unidirectional gene flow from the Near East to Europe alone is insufficient to explain the extra affinity between the Iron Gates HG and the Near-Eastern hunter-gatherers. Thus, it is plausible to assume that prior to 15,000 years ago there was either a bidirectional gene flow between populations ancestral to Southeastern Europeans of the early Holocene and Anatolians of the late glacial or a dispersal of Southeastern Europeans into the Near East. Presumably, this Southeastern European ancestral population later spread into central Europe during the post-last-glacial maximum (LGM) period, resulting in the observed late Pleistocene genetic affinity between the Near East and Europe.



Feldman et al., Late Pleistocene human genome suggests a local origin for the first farmers of central Anatolia, biRxiv, posted September 20, 2018, doi: https://doi.org/10.1101/422295 Source


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