search this blog

Thursday, July 19, 2012

Ancient mtDNA from Western Siberia (aka. Kurgan and Scythian country)


Here's a new paper that describes the genetic shifts that took place on the Baraba Steppe of the West Siberian Plain from the Neolithic to the Iron Age. It's part of an e-book with the latest stable isotope and ancient DNA data from across Eurasia, available free of charge here.

The authors argue that ancient mtDNA and cranial results show at least four different populations making their mark on the Baraba Steppe. These apparently include the aboriginal Western Siberians (carrying mtDNA haplogroups A,C,D and Z), Mesolithic Northeast Europeans from just across the Urals (U2e, U4 and U5), Bronze Age Andronovo nomads from what is now Central Kazakhstan (T, U5 and C), and late Bronze Age/early Iron Age Barabans from Chicha, possibly originally from West Central Asia (showing a wide variety of West Eurasian mtDNA haplogroups).

The analysis of mtDNA samples from the Chicha-1 population revealed some interesting patterns. Crucial changes in the composition of mtDNA haplogroups in the gene pool were observed as compared to the earlier Baraba groups studied (Fig. 3). Dominance of Western Eurasian haplogroups and the near absence of East Eurasian were observed. Additionally, several new West Eurasian haplogroups appeared in the region, including Haplogroups U1a, U3, U5b, K, H, J and W.

The phylogeographic analysis suggests that the distribution and diversification centres of several of these mtDNA haplogroups and specific lineages are located on the west and south west of the Baraba forest steppe region, on the territory corresponding to modern-day Kazakhstan and Western Central Asia (Fig. 10). Apparently, the migration wave from the south strongly influenced the gene pool of the Baraba population in the transitional period from the Bronze to the Early Iron Age.

...

Subsequently, in the Scythian-Sarmatian period, a large cultural group, called the Sargat culture, developed in the region. Its representatives were widespread across the region, from the Ob River to the Urals. Their development represented one of the most significant cultural events in North Asia.


Unlike the authors, however, I don't see any evidence in the paper that points to a southern origin of the Chicha group. In other words, I don't think there's any reason to believe that this population migrated to the Baraba Steppe from West Central Asia across the deserts near the Aral Sea.

In my opinion a more plausible explanation is that this was another wave of settlers from the western steppe of present-day Southern Russia and Ukraine. I suspect they basically followed in the footsteps of the earlier Andronovo groups. Such a scenario would match archaeological evidence, and also various ancient DNA results from Neolithic sites in Ukraine, which have shown most of the mtDNA haplogroups found in the Chicha individuals, like H, U1 and U3 (see, for instance my previous blog entry covering another article from the same e-book).

Indeed, it's interesting that haplogroup T is singled out in this study as a potential maternal marker of the Andronovo nomads from the Baraba Steppe. That's because this haplogroup has already been found among multiple Neolithic remains from Ukraine, and is fairly common today among populations from between the Baltic and Black seas.

The genetic influence of migrants can be detected by the appearance of a new mtDNA haplogroup that was absent in the populations preceding the migration wave. This new mtDNA haplogroup, a West Eurasian T haplogroup, was detected in the Late Krotovo population. The T haplogroup appears simultaneously (with a 15 % frequency) in the Krotovo and Andronovo groups, but was completely absent in all preceding Baraba populations. We therefore consider the appearance of the Haplogroup T-lineage as the most likely genetic marker of the Andronovo migration wave to the region.

This assumption is confirmed by mtDNA studies of Andronovo groups from other West Siberian areas. Haplogroup T lineages were found, with a frequency of 25 %, in the samples (n=16) taken from two Andronovo groups from the Krasnoyarsk and upper Ob River areas.

Citations...

Molodin et al., Human migrations in the southern region of the West Siberian Plain during the Bronze Age: Archaeologcal, palaeogeneic and anthropoloical data, Population Dynamics in Prehistory and Early History (2012), Publication Date: July 2012, ISBN: 978-3-11-026630-6, DOI: 10.1515/9783110266306.93

Ed. by Kaiser, Elke / Burger, Joachim / Schier, Wolfram, Population Dynamics in Prehistory and Early History (2012), Publication Date: July 2012, ISBN: 978-3-11-026630-6, DOI: 10.1515/9783110266306.93

See also...

Ancient mtDNA from the Dnieper-Donets cultural complex

Surprising aDNA results from Neolithic and Bronze Age Ukraine

Ancient Siberians carrying R1a1 had light eyes - take 2


Wednesday, July 18, 2012

Another batch of ancient mtDNA from the Dnieper Basin


This set of results is from a multidisciplinary study on the Mesolithic to Neolithic transition in Ukraine (see here). The mtDNA haplogroups include two C, two T, one U3 and one probable U1.

The paper is part of an open access e-book which features many other articles on prehistoric Europe and Asia: Population Dynamics in Prehistory and Early History (2012).

Despite the small sample and lack of Y-DNA data, I'd say that this is a fairly useful effort. That's because it again shows the presence of South Siberian-specific maternal lineages on the North Pontic steppe during the Neolithic, and gives weight to the scenario that there was a movement of people from the east of the Urals to Europe at a very early timeframe (for more on that, see here and here).

East Eurasian lineages were represented by the C clade (Ya34 and Ya45), which is uncommon in ancient or present-day European populations, but is found in Neolithic populations, as well as contemporary populations from South Siberia, where this lineage is most likely originated (Starikovskaya et al., 2005; Mooder et al., 2006).

Of interest in this context is the fact that the analysis of Neolithic cemeteries of the Baikal region has suggested that a depopulation event occurred in that region during the 6th millennium BP (Mooder et al., 2006). As such, the dating of Yasinovatka (at ca. 6440–6080 [Hedges et al., 1995]) suggests that there is a possible link between the Baikal depopulation event and the appearance of the C lineage of mtDNA in the North Pontic region.

Citations...

Lillie, Malcolm C et al., Prehistoric populations of Ukraine: Migration at the later Mesolithic to Neolithic transition, Population Dynamics in Prehistory and Early History (2012), Publication Date: July 2012, ISBN: 978-3-11-026630-6, DOI: 10.1515/9783110266306.93

Ed. by Kaiser, Elke / Burger, Joachim / Schier, Wolfram, Population Dynamics in Prehistory and Early History (2012), Publication Date: July 2012, ISBN: 978-3-11-026630-6, DOI: 10.1515/9783110266306.93


See also...

Ancient mtDNA from Western Siberia (aka. Kurgan and Scythian country)