Tuesday, January 9, 2018

Slavs Are Genetically All The Same, Siberians Are Each Distinct In Their Own Way

The Slavic people are generally almost identical genetically (except for Russian Starovers who have 5%-10% Central Siberian admixture). This is notable since Slavic expansion happened starting about 1500 years ago, suggesting a replacement scenario for large swaths of territory during the Migration Period in Europe, rather than fixation reach through spouse exchange between genetically diverse populationos over a long period of time.

Siberian populations show Turkic, Uralic and Indo-European contributions in ways that are complex. Some language groups are genetically connected across long distances with some instances of language shift, and some populations are particularly complex mixes of multiple populations. In these cases, the Turkic genetic contribution is the late arrival to the party (although still more recent arrivals for most of their range than the Slavs), coming thousands of years after the Uralic and Indo-European presences in most of this region.
Background: The history of human populations occupying the plains and mountain ridges separating Europe from Asia has been eventful, as these natural obstacles were crossed westward by multiple waves of Turkic and Uralic-speaking migrants as well as eastward by Europeans. Unfortunately, the material records of history of this region are not dense enough to reconstruct details of population history. These considerations stimulate growing interest to obtain a genetic picture of the demographic history of migrations and admixture in Northern Eurasia. 
Results: We genotyped and analyzed 1076 individuals from 30 populations with geographical coverage spanning from Baltic Sea to Baikal Lake. Our dense sampling allowed us to describe in detail the population structure, provide insight into genomic history of numerous European and Asian populations, and significantly increase quantity of genetic data available for modern populations in region of North Eurasia. Our study doubles the amount of genome-wide profiles available for this region. 
We detected unusually high amount of shared identical-by-descent (IBD) genomic segments between several Siberian populations, such as Khanty and Ket, providing evidence of genetic relatedness across vast geographic distances and between speakers of different language families. Additionally, we observed excessive IBD sharing between Khanty and Bashkir, a group of Turkic speakers from Southern Urals region. While adding some weight to the “Finno-Ugric” origin of Bashkir, our studies highlighted that the Bashkir genepool lacks the main “core”, being a multi-layered amalgamation of Turkic, Ugric, Finnish and Indo-European contributions, which points at intricacy of genetic interface between Turkic and Uralic populations. Comparison of the genetic structure of Siberian ethnicities and the geography of the region they inhabit point at existence of the “Great Siberian Vortex” directing genetic exchanges in populations across the Siberian part of Asia. 
Slavic speakers of Eastern Europe are, in general, very similar in their genetic composition. Ukrainians, Belarusians and Russians have almost identical proportions of Caucasus and Northern European components and have virtually no Asian influence. 
We capitalized on wide geographic span of our sampling to address intriguing question about the place of origin of Russian Starovers, an enigmatic Eastern Orthodox Old Believers religious group relocated to Siberia in seventeenth century. A comparative reAdmix analysis, complemented by IBD sharing, placed their roots in the region of the Northern European Plain, occupied by North Russians and Finno-Ugric Komi and Karelian people. Russians from Novosibirsk and Russian Starover exhibit ancestral proportions close to that of European Eastern Slavs, however, they also include between five to 10 % of Central Siberian ancestry, not present at this level in their European counterparts. 
Conclusions: Our project has patched the hole in the genetic map of Eurasia: we demonstrated complexity of genetic structure of Northern Eurasians, existence of East-West and North-South genetic gradients, and assessed different inputs of ancient populations into modern populations.
Triska et al., Between Lake Baikal and the Baltic Sea: genomic history of the gateway to Europe, BMC Genetics, 2017 18(Suppl 1):110, https://doi.org/10.1186/s12863-017-0578-3

Hat tip to Davidski at Polishgenes Blog. A comment from that post is notable:
Slumbery said... 
The modern Bashkirs live where Hungarians lived before moving west and probably this is the place where their Turkic-Uralic "amalgam" formed. (At least the elite of the end 9th century conquerors was such an amalgam.) Among the sampled populations Khanty are the closest to modern Hungarian linguistically. (The actual closest is Southern Mansi, but that population is not sampled here.) So it makes some historical sense that among the sampled Uralic speaking populations Khanty have the most IBD sharing with Bashkirs. 
January 6, 2018 at 8:53 PM

1 comment:

Ryan said...

What I'd really be curious about with respect to the Bashkir is the R1b(xM269) there, and if there's a layer of ancestry that predates IE and Uralic that can be discerned.