I could only access the Abstract of this one, and a little more at the link. Good reading though..
Differentiation of the Mitochondrial Subhaplogroup U4 in the Populations of Eastern Europe, Ural, and Western Siberia: Implication to the Genetic History of the Uralic Populations
B. A. Malyarchuk1
Institute of the Biological Problems of the North, Russian Academy of Sciences, Magadan, 685000, Russia
Abstract Phylogenetic relationships between the sequences of the mitochondrial DNA (mtDNA) hypervariable segment 1, belonging to subhaplogroup U4, were examined in the populations of Eastern Europe, Ural, and Northwest Siberia. It was shown that the frequency of subhaplogroup U4, as well as its proportion in the U-component of the gene pools, increased eastwards, reaching maximum values in the populations of Northwest Siberia. Phylogenetic analysis it was showed that the appearance of specific U4-lineage (16113C–16356–16362) in the ancestors of Mansi was most likely caused by its divergence from the East European cluster 16356–16362 in the Late Upper Paleolithic (18566 ± 12915 years before present). Other U4 mtDNA lineages (16189–16356 and 16311–16356), typical mostly of the indigenous populations of Northwest Siberia (Mansi, Nganasans, and Kets) may have formed during the Neolithic–early Bronze Age (6055 ± 3599 years before present, on average). It seems likely that the isolation of ancient populations inhabiting the region between the Ob'' and Yenisei rivers was the key factor, providing the appearance of the unique Caucasoid mtDNA lineages in their gene pools. These results were consistent with the traditional point of view on the mixed origin of the Finno-Ugric populations of the Volga–Ural region and West Siberia, resulted from the genetic relationships between the populations of Europe and Asia.