Abstract

The history of human populations occupying 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, material records of history of this region are not dense enough to reconstruct details of population history. These considerations stimulate growing interest to obtain genetic picture of demographic history of migrations and admixture in Northern Eurasia. We genotyped and analyzed 1079 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 amount of genetic data available for modern populations in region of North Eurasia. This 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 Bashkirs, a group of Turkic speakers from Southern Urals region, supporting the hypothesis of domination of autochthonous genetic roots of Bashkirs.

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. Russians from Novosibirsk and Russian Starover (Eastern Orthodox Old Believers, an enigmatic religious orthodox group relocated to Siberia in 17th century) exhibit ancestral proportions close to that of Ukrainians and Belarusians. However, unlike other Eastern European Slavs, both populations of Siberian Russians include between five to ten percent of Central Siberian ancestry. Consideration of f3 statistics suggested that populations ancestral to contemporary Ukrainians participated in the formation of Volga-Ural populations, although probably to a lesser extent than ancestors of Belarusians.

Finally, we capitalized on wide geographic span of our sampling to address intriguing question about place of origin of Russian Starovers. Our comparative reAdmix analysis, complemented by IBD sharing, placed their roots to the region of Northern European Plain, occupied by North Russians and Finno-Ugric Komi and Karel people. Russians from Novosibirsk and Russian Starover exhibit ancestral proportions close to that of European Eastern Slavs, however, they also include between five to ten percent of Central Siberian ancestry, not present at this level in their European counterparts.