December 03, 2005

mtDNA of Neolithic Siberians from Lake Baikal

A new article for the Ancient DNA Compendium. Geneticists have studied the genetic structure of Neolithic Mongoloids from the Lake Baikal region. It was previously thought that there was an 800-year "gap" in the occupation of the studied region, and the mtDNA data supports this theory, because populations before, and after this gap were quite different in their mtDNA profiles. Here are the haplogroup frequencies:

Free Image Hosting at www.ImageShack.us

Interesting quote about the continuity of population from the Neolithic to the Hun period:
Russian scholars generally believe that the Xiongnu were immigrants who did not interact with the indigenous groups in the region (Okladnikov, 1964). However, the similarity of Serovo-Glazkovo and Xiongnu mtDNA haplogroup distributions suggests that gene flow may have occurred between matrilineal descendents of the Serovo-Glazkovo and groups representing the northern extent of the Huns. This association is compelling, as it suggests that temporal stability was maintained in the regional matrilineal gene pool of Lake Baikal for over four millennia (i.e., from 4200 BC–200 AD).
And on possible non-Mongoloid elements in the population:
The only definitive non-East Eurasian haplogroup identified in either population is haplogroup U5a. The geographic origins of haplogroup U5a are ambiguous, as it has been observed in both West and East Eurasian populations (Richards et al., 1998; Sykes, 1999; Derenko et al., 2002b, 2003), but it has great temporal depth. This haplogroup was detected both in many modern Siberian groups (e.g., Derbeneva et al., 2002a,b; Derenko et al., 2003; Pakendorf et al., 2003; Schurr et al., 2004) and in other prehistoric Asian cemetery populations (e.g., Oota et al., 1999; Keyser-Tracqui et al., 2003). By exploring the geographic origins of haplogroup U5a, it may be possible to reveal another facet of Siberian population history.

Am J Phys Anthropol. 2005 Dec 1; [Epub ahead of print]

Population affinities of Neolithic Siberians: A snapshot from prehistoric Lake Baikal.

Mooder KP, Schurr TG, Bamforth FJ, Bazaliiski VI, Savel'ev NA.

Archaeological evidence supports the inhabitation of the Lake Baikal region since the Paleolithic. Both metric and nonmetric osteological studies suggest that Neolithic Cis-Baikal populations are the ancestors of contemporary inhabitants of the region. To date, ancient DNA data have not been used to corroborate this biological continuity hypothesis. This study presents a temporal snapshot of the Cis-Baikal Neolithic by examining mtDNA diversity in two cemetery populations situated on the Angara River downstream of Lake Baikal. The 800 years separating the use of the two cemeteries is thought to represent a biocultural hiatus in the Cis-Baikal region, one that ended when a new group migrated into the area. To assess the likelihood that genetic continuity exists between these two Neolithic groups, we examined both mtDNA coding region and hypervariable region I (HVI) polymorphisms from skeletal remains excavated from both cemeteries (Lokomotiv and Ust'-Ida). The mtDNA haplogroup distributions of the two cemetery populations differ significantly, suggesting that they were biologically distinct groups. When the biological distance between these Neolithic groups is compared with modern Siberian and other East Eurasian groups, the posthiatus group (Serovo-Glazkovo) generally aligns with contemporary Siberians, while the prehiatus (Kitoi) individuals are significantly different from all but modern Kets and Shorians living in the Yenisey and Ob River basins to the west of Lake Baikal. These results suggest that the Lake Baikal region experienced a significant depopulation event during the sixth millennium BP, and was reoccupied by a new immigrant population some 800 years later.

Link

No comments: