The genetic legacy of the expansion of Turkic-speaking nomads across Eurasia

PLoS Genet. 2015 Apr 21;11(4):e1005068. doi: 10.1371/journal.pgen.1005068. eCollection 2015 Apr.

Abstract

The Turkic peoples represent a diverse collection of ethnic groups defined by the Turkic languages. These groups have dispersed across a vast area, including Siberia, Northwest China, Central Asia, East Europe, the Caucasus, Anatolia, the Middle East, and Afghanistan. The origin and early dispersal history of the Turkic peoples is disputed, with candidates for their ancient homeland ranging from the Transcaspian steppe to Manchuria in Northeast Asia. Previous genetic studies have not identified a clear-cut unifying genetic signal for the Turkic peoples, which lends support for language replacement rather than demic diffusion as the model for the Turkic language's expansion. We addressed the genetic origin of 373 individuals from 22 Turkic-speaking populations, representing their current geographic range, by analyzing genome-wide high-density genotype data. In agreement with the elite dominance model of language expansion most of the Turkic peoples studied genetically resemble their geographic neighbors. However, western Turkic peoples sampled across West Eurasia shared an excess of long chromosomal tracts that are identical by descent (IBD) with populations from present-day South Siberia and Mongolia (SSM), an area where historians center a series of early Turkic and non-Turkic steppe polities. While SSM matching IBD tracts (> 1cM) are also observed in non-Turkic populations, Turkic peoples demonstrate a higher percentage of such tracts (p-values ≤ 0.01) compared to their non-Turkic neighbors. Finally, we used the ALDER method and inferred admixture dates (~9th-17th centuries) that overlap with the Turkic migrations of the 5th-16th centuries. Thus, our results indicate historical admixture among Turkic peoples, and the recent shared ancestry with modern populations in SSM supports one of the hypothesized homelands for their nomadic Turkic and related Mongolic ancestors.

Publication types

  • Historical Article
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asia
  • Asian Continental Ancestry Group / genetics
  • Asian Continental Ancestry Group / history
  • China
  • Chromosomes / genetics*
  • Chromosomes, Human, Y / genetics
  • Ethnic Groups / genetics
  • Ethnic Groups / history
  • Europe
  • Gene Flow*
  • Genetics, Population*
  • Genotype
  • History, 15th Century
  • History, 16th Century
  • History, 17th Century
  • History, Medieval
  • Human Migration / history*
  • Humans
  • Language
  • Middle East
  • Mongolia
  • Polymorphism, Single Nucleotide / genetics
  • Siberia

Grant support

This work was supported by European Union European Regional Development Fund through the Centre of Excellence in Genomics for the Estonian Biocentre and the University of Tartu, by the Estonian Institutional Research grant IUT24-1, by the European Commission grant 205419 ECOGENE to the EBC, by the Estonian Science Foundation grant nr8973, and by the Estonian Basic Research Grant SF 0270177s08; Russian Federation President Grant for young scientists (MK-2845.2014.4) to BY; the Russian Academy of Sciences Program for Fundamental Research "Biodiversity and dynamics of gene pools" to EK; the Federal Agency of Education and Science of the Russian Federation (state contracts 02.740.11.0701 and P325 to EK); the Russian Foundation for Basic Research (grant number 11-04-00652_a to EK); the Russian Foundation for Humanities (grant number 13-11-02014/U to EK); Committee for Coordination Science and Technology Development of Republic of Uzbekistan (grant number FA-A6-T180 to ST); EGC-UT received targeted financing from Estonian Government SF0180142s08, Center of Excellence in Genomics (EXCEGEN), and University of Tartu (SP1GVARENG). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.