Between Lake Baikal and the Baltic Sea: genomic history of the gateway to Europe

Abstract

BackgroundThe 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.ResultsWe 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.ConclusionsOur project has patched the hole in the genetic map of Eurasia: we demonstrated complexity of genetic structure of Northern...

Diverse genetic origins of medieval steppe nomad conquerors

“…The datasets were stratified into 6 cohorts by the estimated age of the samples: 0-1000 BC, 1000-2000 BC, 2000-3000 BC, 3000-4000 BC, 4000-5000 BC, and above 5000 BC. We used worldwide reference data from several sources [11,25,28,51] to compile a dataset of modern populations. The datasets were converted into suitable formats for NGSadmix [26,52], reAdmix [26], and TreeMix [53] analyses.…”

“…Therefore, data from the presentday population should be geographically informative for Khazars. Therefore, to understand Khazar origins, we synthesized a reference panel of 1,933 individuals representing 56 Eurasian populations from previously published data that were genotyped using Illumina Infinium arrays [11,28], which intersected at 120,278 polymorphic sites.…”

“…It was supplemented with the Eurasian dataset [28], adding 1076 samples collected in different parts of Russia, Kazakhstan, Georgia, Uzbekistan, and Kyrgyzstan. These samples were genotyped on the Illumina Infinium 370-Duo, 370-Quad, or 610-Quad arrays.…”

“…For the purpose of comparison with previous studies, we retained the names of the components, although they may not be an accurate representation of ancestry. The Geno 2.0 database was supplemented with the Eurasian dataset [28], adding 1076 samples collected in different parts of Russia, Kazakhstan, Georgia, Uzbekistan, and Kyrgyzstan. These samples were genotyped on the Illumina Infinium 370-Duo, 370-Quad, or 610-Quad arrays.…”

Diverse genetic origins of medieval steppe nomad conquerors – a response to Mikheyev et al. (2019)

“…Regretfully, the authors have failed to report the samples which they analyze, as is the standard in population genetic studies. Some of their samples (Triska et al 2017) are unavailable. Key populations in the Khazar scenery are missing, such as Bulgarians (Yunusbayev et al 2011), more Turkish populations (Hodoglugil and Mahley 2012), Mongols (Pagani et al 2016), and populations that currently inhabit the ancient lands of the Western Turkic Khaganate from where the Khazars have emerged like Tajiks (Yunusbayev et al 2011) and Western Asian populations (Conrad et al 2006).…”