Informative study on the populations of Sakha Republic (Yakutia) and Siberia in general:
Sardana A. Fedorova et al., Autosomal and uniparental portraits of the native populations of Sakha (Yakutia): implications for the peopling of Northeast Eurasia. BMC Evolutionary Biology 2014. Open access → LINK [doi:10.1186/1471-2148-13-127]
Sakha – an area connecting South and Northeast Siberia – is significant for understanding the history of peopling of Northeast Eurasia and the Americas. Previous studies have shown a genetic contiguity between Siberia and East Asia and the key role of South Siberia in the colonization of Siberia.
We report the results of a high-resolution phylogenetic analysis of 701 mtDNAs and 318 Y chromosomes from five native populations of Sakha (Yakuts, Evenks, Evens, Yukaghirs and Dolgans) and of the analysis of more than 500,000 autosomal SNPs of 758 individuals from 55 populations, including 40 previously unpublished samples from Siberia. Phylogenetically terminal clades of East Asian mtDNA haplogroups C and D and Y-chromosome haplogroups N1c, N1b and C3, constituting the core of the gene pool of the native populations from Sakha, connect Sakha and South Siberia. Analysis of autosomal SNP data confirms the genetic continuity between Sakha and South Siberia. Maternal lineages D5a2a2, C4a1c, C4a2, C5b1b and the Yakut-specific STR sub-clade of Y-chromosome haplogroup N1c can be linked to a migration of Yakut ancestors, while the paternal lineage C3c was most likely carried to Sakha by the expansion of the Tungusic people. MtDNA haplogroups Z1a1b and Z1a3, present in Yukaghirs, Evens and Dolgans, show traces of different and probably more ancient migration(s). Analysis of both haploid loci and autosomal SNP data revealed only minor genetic components shared between Sakha and the extreme Northeast Siberia. Although the major part of West Eurasian maternal and paternal lineages in Sakha could originate from recent admixture with East Europeans, mtDNA haplogroups H8, H20a and HV1a1a, as well as Y-chromosome haplogroup J, more probably reflect an ancient gene flow from West Eurasia through Central Asia and South Siberia.
Our high-resolution phylogenetic dissection of mtDNA and Y-chromosome haplogroups as well as analysis of autosomal SNP data suggests that Sakha was colonized by repeated expansions from South Siberia with minor gene flow from the Lower Amur/Southern Okhotsk region and/or Kamchatka. The minor West Eurasian component in Sakha attests to both recent and ongoing admixture with East Europeans and an ancient gene flow from West Eurasia.
The matrilineal mitochondrial DNA pool is dominated by C4, C5, D4 and D5, with some instances of other lineages (see fig. 1). All these and most of the rest are common Siberian lineages of East Asian roots.
In the odd zone, the extremely rare haplogroup R3 has been found among North Yuhaghirs in this study (previously only in Jordan that I know with any certainty). They mention that R3 and R1 are derived from the same root, sharing two coding region mutations, and therefore they proceed to rename R3 as R1b. R1 is an also rare Indian matrilineage.
The patrilineal Y-DNA pool (see fig. 2) is massively dominated by N1c, which also dominates most Uralic-speaking peoples. This is unusual for a Turkic-speaking population but it was known since long ago. Other still important lineages are C2 (former C3, typical of NE Asia and some North American populations), N1b and R1a. Some instances of I, E1b1b1, J, O, F and L are also reported. C2 is more important among the Northern (non-Turkic) populations of Sakha Republic, reaching to 30-40%.
On the autosomal DNA pool, the heatmat (fig. 4) shows that among all sampled populations the Selkup are particularly isolated. Koryaks and Chukchis from the far NE Siberia form a small cluster of their own and so do Shors and Kets (West Siberians). Native American populations also show great individual isolation in comparison with most Eurasians.
Otherwise there are three major clusters: West/South/Central Eurasians, East Asians and Siberians, who generally also cluster with East Asians.
Some of this is also apparent in the PCA (fig. 5) although not as neatly:
|PCA of the native populations of Sakha in the context of other Eurasian and American populations.|
Maybe more illustrative is the ADMIXTURE analysis:
|ADMIXTURE plots. Ancestry proportions of the 758 individuals studied (from 55 populations) as revealed by the ADMIXTURE software at K = 3, K = 4, K = 6, K = 8, and K = 13.|
The analysis reveals, from K=6 upwards, the following clusters: West Eurasian (dark blue), South Asian (green), East Asian (orange, also light green at K=13) and several Siberian and Native American specific clusters (yellow, light and dark brown, red, etc.)
The persistance of the blue West Eurasian component in Aleutians and Greenlanders should raise some eyebrows. However, Greenlanders do not really cluster with West Eurasians in the heatmap, so this is almost certainly an artifact that indicates that a much greater K-depth should be achieved in order to properly classify this most diverse human sample. Thirteen clusters are obviously not enough.