The Turkic Expansion

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Genetic Evidence

Here is an overview of some research about genetic evidence regarding the Turkic expansion:

Historical documents reveal that the Turkic expansion occurred; however, details of the specific nature of the expansion and its influence on the people of the areas that the Turks entered are difficult to decipher. Genetic evidence can reveal much about the admixture of populations, and thus, is useful for determining facts about the Turkic expansion that were not recorded in history.

Multiple studies have been done looking at the mtDNA data from Central Asian and Turkic populations (Calafell et al., 1996; Simoni et al., 2000. These provide helpful clues as to the role of women in the Turkic expansion, and the origin of maternal lineages in Turkic populations. Comas et al (1998) confirmed from their data that Central Asian populations (Uighurs, Kazakhs, and Kirghiz) do in fact possess intermediate mtDNA markers between European and east Asian populations. They also concluded that the Turkic expansion into Anatolia must have been one of elite dominance, since the presence of Central Asian mtDNA markers in modern Anatolia includes only the amount of Asian influence that may be expected from the original expansion from the original movement of human populations from the Middle East to Europe. However, these data only reflect the maternal lineage of Central Asian and Turkish populations. It is commonly held that the Turkic expansion took place as a series of military exploits, which is usually a male enterprise. This suggests that if this view is correct, paternal lineage contributions to the gene pool, as in the Y-chromosome, would be significantly greater than the maternal lineage contributions.

In their study, Di Benedetto et al (2001) explored the influence of Central Asian populations' genetic influence in Anatolia by analyzing y-chromosome data. In their study they note that although a significant linguistic barrier exists between Turkey and all of its neighbors (Syria, Iraq, Iran, Georgia, Armenia, Bulgaria and Greece), no significant genetic differences have been found between Turkish and other European populations. According to linguistic relatedness, however, Turkish populations in Anatolia should also be somewhat genetically similar to other Turkic speaking populations, or Central Asian populations. Through their analyses they found that the elite dominance theory of admixture between Central Asian and Anatolian populations does not hold up from the y-chromosome data. They propose the “continuous immigration theory”, which proposes admixture across many generations with continuous input from Central Asian genes throughout the generations (154). It is estimated that genes of Central Asian origin comprise 30% of the gene pool in present day Anatolia. For that amount of admixture to occur, there would only need to be a 1% contribution of Central Asian genes throughout many generations (152). This conclusion also matches what is known about interaction between Central Asian and Anatolian populations historically. Therefore, by looking at both the mtDNA and y-chromosome data, it is clear that Turkic peoples, though defined by their linguistic affiliation, are not genetically homogenous, but rather reflect the historical expansions. As their gene pools reflect intermediate data between east Asian and European populations, so does the Turkish population of Anatolia reflect admixture consistent with historical accounts.

            One may wonder why so much focus is placed on populations in Anatolia, since they are only one piece of the greater Turkic expansion puzzle. Anatolia is a region far separated from the place of origin of Turkic speaking peoples in northeast Asia. It has been a place of extensive contact between different populations, as it serves as a land bridge connecting Europe and the Middle East. However, its linguistic affiliation is completely separate from any of its surrounding peoples. Turkish is a member of the Turkic branch of the Altaic linguistic family. Turkey’s neighboring nations all speak either Arabic, a Semitic language; Indo European languages such as Persian, Greek, and Bulgarian; or Caucasian, such as Georgian. Modern day Turkey seems to be the farthest reach of the Turkic expansion, as evidenced by the linguistic data. It is, therefore, also useful to examine the genetic data to discover whether the genetic evidence correlates with the linguistic evidence. This genetic evidence demonstrates that the Turkic expansion was not merely a cultural expansion, but also a genetic and actual expansion of peoples over many generations.

            The next step pf research in this area would be an in-depth comparison of the genetic relatedness of “outlying” Turkic populations, such as the Turkmens of Iran or the Tatars of Russia to Central Asian populations. This would provide further evidence for the either correlation of linguistic data to genetic data, or the separate nature of the two in this particular world event.

 

 

 

 

Works Cited

 

Calafell, F. et al. 1996. From Asia to Europe: mitochondrial DNA sequence variability in

Bulgarians and Turks. Annals of Human Genetics. 60: 35-49.

Comas, David et al. 1998. Trading Genes along the Silk Road: mtDNA Sequences and

the Origin of Central Asian Populations. American Journal of Human Genetics.

63:1824-1838.

Di Benedetto, Giulietta et al. 2001. DNA diversity and Population admixture in Anatolia.

American Journal of Physical Anthropology. 115: 114-156.

Simoni, L. et al. 2000. Geographic patterns of mtDNA diversity in Europe. American

             Journal of Human Genetics. 66: 262-278.

 

Work Consulted

Önengüt, S. et al. 2000. Deletion pattern in the dystrophin gene in Turks and a

comparison with Europeans and Indians. Annals of Human Genetics. 64: 33-40.