MTDNA VARIATION OF ABORIGINAL SIBERIANS REVEALS DISTINCT GENETIC AFFINITIES WITH NATIVE-AMERICANS

The mtDNA variation of 411 individuals from 10 aboriginal Siberian pop ulations was analyzed in an effort to delineate the relationships betw een Siberian and Native American populations. All mtDNAs were characte rized by PCR amplification and restriction analysis, and a subset of t hem was characterized by control region sequencing. The resulting data were then compiled with previous mtDNA data from Native Americans and Asians and were used for phylogenetic analyses and sequence divergenc e estimations. Aboriginal Siberian populations exhibited mtDNAs from t hree (A, C, and D) of the four haplogroups observed in Native American s. However, none of the Siberian populations showed mtDNAs from the fo urth haplogroup, group B. The presence of group B deletion haplotypes in East Asian and Native American populations but their absence in Sib erians raises the possibility that haplogroup B could represent a migr atory event distinct from the one(s) which brought group A, C, and D m tDNAs to the Americas. Our findings support the hypothesis that the fi rst humans to move from Siberia to the Americas carried with them a li mited number of founding mtDNAs and that the initial migration occurre d between 17,000-34,000 years before present.