These results appear to be consistent with my own estimate of 1/7 Central Asian ancestry for Anatolian Turks. In a more recent analysis based on haplotype sharing, I have discovered that there is some sub-structure within the Turkish population, with the emergence of three tendencies: a central group of Anatolian Turks, a group of Turks with partial origin from the Balkans, and a group of Turks from northeastern Anatolia. As more project participants join the Dodecad Project, we will learn much more on the structure of the Turkish population and its relationships with its geographical neighbors and linguistic relatives.
Annals of Human Genetics DOI: 10.1111/j.1469-1809.2011.00701.x
Turkish Population Structure and Genetic Ancestry Reveal Relatedness among Eurasian Populations
Uğur Hodoğlugil, Robert W. Mahley
Turkey has experienced major population movements. Population structure and genetic relatedness of samples from three regions of Turkey, using over 500,000 SNP genotypes, were compared together with Human Genome Diversity Panel (HGDP) data. To obtain a more representative sampling from Central Asia, Kyrgyz samples (Bishkek, Kyrgyzstan) were genotyped and analysed. Principal component (PC) analysis reveals a significant overlap between Turks and Middle Easterners and a relationship with Europeans and South and Central Asians; however, the Turkish genetic structure is unique. FRAPPE, STRUCTURE, and phylogenetic analyses support the PC analysis depending upon the number of parental ancestry components chosen. For example, supervised STRUCTURE (K= 3) illustrates a genetic ancestry for the Turks of 45% Middle Eastern (95% CI, 42–49), 40% European (95% CI, 36–44) and 15% Central Asian (95% CI, 13–16), whereas at K= 4 the genetic ancestry of the Turks was 38% European (95% CI, 35–42), 35% Middle Eastern (95% CI, 33–38), 18% South Asian (95% CI, 16–19) and 9% Central Asian (95% CI, 7–11). PC analysis and FRAPPE/STRUCTURE results from three regions in Turkey (Aydin, Istanbul and Kayseri) were superimposed, without clear subpopulation structure, suggesting sample homogeneity. Thus, this study demonstrates admixture of Turkish people reflecting the population migration patterns.