Ivan Nasidze and Mark Stoneking, along with a half dozen or so other colleagues, have studied the mitochondrial and Y-chromosome diversity of the Talysh. They’ve published their analysis in the American Journal of Physical Anthropology. The paper can be found under this title, “mtDNA and Y-chromosome variation in the Talysh of Iran and Azerbaijan.”
The Talysh are an ethnic Iranian group who speak a language that most Talysh identify as Tolish. Not surprisingly, Tolish is an Iranian language, which its origins can be traced back to Medean empire. Currently, the Talysh people can be found in northern Iran — in and around Gilan and Ardabil as well as southern Azerbaijan, i.e. the Lenkoran, Astaran, Lerik, and Massalin districts. Between these two physically separated populations, there exists a big linguistic rift. There’s some loose evidence that both the northern and southern dialects are a hodge-podge of other regional languages. Some, like Donald Stilo, have suggested the two dialects should be considered their own respective languages because they are so different.
Since linguistic differences often manifest along with genetic differences (check out the Spitton’s ‘Genes and Languages: Not So Strange Bedfellows?‘ post), Nasidze et al. investigated the mtDNA and Y-chromosome of the Talish and compared their results to other groups in Iran and the Caucasus. 377 bp of the hypervariable 1 region of the mitochondrial genome was a target, as well as 10 SNPs on the Y-Chromosome from 50 Talysh from Iran and 78 Talysh from Azerbaijan, for sequencing. The sequences have been submitted to Genbank.
Compared to Gilaki, Mazandarani, Turkmen and people from the rest of the Iran and southern Caucasus regions, the mtDNA of both northern and southern Talysh are closely related to each other and neighboring groups. In other words, there’s high amounts of variation with these groups than between these groups for the mitochondrial analysis… which doesn’t support genetic differentiation of the two groups.
But, the variations in the Y-Chromosome of northern Talysh differ from neighboring groups. Southern Talysh Y-Chromosome are very similar to other Iranian groups. The northern Talysh group most closely with Turkmen. Could there have been men from Turkmenistan migrating and influencing the genetic and linguistic composition of the northern Talysh? Sure, about 1,000 years ago, Turkic-speakers, like the Oguz hauled over to the souther Caucasus bringing over Turkic language — now seen in Azeri and Turkish.
But since the Talysh retained an Iranian language, this is scenario may not have been reality. Remember, people, more often than not, reproduce within their linguistic groups… especially in the past. Furthermore, the haplotypes associated with the Y-Chromosome SNPs M172 and M173 do not support a relationship between northern Talysh and Turkmen. Rather, the shared resemblances M172 and M173, are considered to be a by product of genetic drift, either from a founder effect with the initial migrations into Azerbaijan or because of reduced population sizes.
Since Nasidze et al. could not find any genetic evidence supporting the linguistic divergence between northern and sothern Talysh, they suggest that the differences between the two dialects are due to internal linguistic changes, such as contact with other languages. They recommend an in depth analysis/comparison of dialects to figure exactly why the two are so different. Aside from this conclusion, they do add to the history of the Talysh, one where there was most likely a male-limited bottleneck in the founding of the northern Talysh.
I’ve been trying to do some historical research to see if there’s any documented genocide or war in which Talysh populations have plumeted, something that would affect their genetic diversity. According to census from the Soviety Union, between 1926 and 1989, the population of Talysh speaking peoples in Azerbaijan dropped from 77,039 to 21,914. Could this be the drop that affected the genetic diversity of the Talysh? Anyone know the history of the Talysh a bit more?
Nasidze, I., Quinque, D., Rahmani, M., Alemohamad, S.A., Asadova, P., Zhukova, O., Stoneking, M. (2008). mtDNA and Y-chromosome variation in the Talysh of Iran and Azerbaijan. American Journal of Physical Anthropology DOI: 10.1002/ajpa.20903