Clear signals of European admixture in Central Asia via autosomal DNA, mtDNA and even teeth...so where's the European Y-DNA?

For the past few years I've regularly blogged about ancient European migrations to Central and East Asia. It's actually fairly easy to pick up signals of these population movements via autosomal DNA, mtDNA, and even physical traits (for example, see here and here). However, it's a lot harder to do so via Y-DNA. Indeed, to date, there have been few instances of European specific Y-chromosome results from Central Asia, like R1a-Z280. And all of these can be attributed, at least in theory, to late Russian incursions. So what happened to the European paternal lineages in Asia, which might be expected to exist there today in fair numbers based on other genetic and archeological data?

I've always suspected that they were replaced during later Turkic and Altaic expansions from east to west, via ethnic cleansing of the males. It seems like an extreme scenario, but I think it's a very plausible one in the context of the times. Ancient Y-chromosome data shows very clearly that Eurasian steppe nomads were highly patrilineal. For instance, almost all of the European-like Andronovo kurgan remains successfully tested for Y-DNA have come back R1a (we just don't know which subclade yet). What if the Asian groups coming from the east were just as patrilineal? Indeed, it looks like they were.

Genetic snapshot from ancient nomads of Xinjiang.

HONGJIE LI1, SHIZHU GAO2, CHUNXIANG LI1, YE ZHANG1, WEN ZENG3, DONG WEI3 and HUI ZHOU1,3.

Nomads of the Eurasian steppes are known to have played an important role in the transfer commodities and culture among East Asia, Central Asia, and Europe. However, the organization of nomadic societies and initial population genetic composition of nomads were still poorly understood because of few archaeological materials and written history.

In this study, the genetic snapshot of nomads was emerged by examining mitochondrial DNA and Y-chromosome DNA of 30 human remains from Heigouliang (HGL) site in the eastern of Xinjiang, which dated 2000 years ago and associated to the nomadic culture by archaeological studies. Mitochondrial DNA analysis showed that the HGL population included both East Eurasian haplogroups (A, C, D, G, F and Z) and West Eurasian haplogroups (H, K, J, M5 and H). The component of Eastern haplogroups is dominant. The distribution frequency and Fst values of Eastern haplogroups indicated the HGL population presented close genetic affinity to the nearby region modern populations of Gansu and Qinghai, while those of western haplogroups showed similar with Mongolia and Siberia populations. The results implied various maternal lineages were introduced into the HGL population. Regarding the Y chromosomal DNA analysis, nearly all samples belonged to haplogroup Q which is thought to be the mark of the Northern Asian nomads. We identified paternal kinship among three individuals at the same tomb by Y-STR marker.

Combined with archaeological and anthropological investigations, we inferred that the gene flow from the neighboring regions was possibly associated with the expansion of Xiongnu Empire.

The above abstract comes from the 81st Annual Meeting of the American Association of Physical Anthropologists program. Not only does it show that Iron Age Asian nomads were patrilineal, it also proves that they absorbed groups of West Eurasian, and possibly European origin, thus affecting their own mtDNA haplogroup composition in the process, but not their Y-DNA haplogroup frequencies.

I suspect that ethnic cleansing of males has shifted profoundly the character of Y-DNA composition across Central Asia at least a couple of times since the LGM. But to uncover these shifts, we'll need lots of ancient Y-DNA, from different periods, and at a fairly high resolution.