The Genetic Legacy of Paleolithic Homo sapiens sapiens in Extant Europeans

The Genetic Legacy of Paleolithic Homo sapiens sapiens in Extant Europeans: A Y Chromosome Perspective

Ornella Semino,1,2*† Giuseppe Passarino,2,3† Peter J. Oefner,4 Alice A. Lin,2 Svetlana Arbuzova,5 Lars E. Beckman,6 Giovanna De Benedictis,3 Paolo Francalacci,7 Anastasia Kouvatsi,8 Svetlana Limborska,9 Mladen Marcikiæ,10 Anna Mika,11 Barbara Mika,12 Dragan Primorac,13 A. Silvana Santachiara-Benerecetti,1 L. Luca Cavalli-Sforza,2 Peter A. Underhill2, published 2000.

A genetic perspective of human history in Europe was derived from 22 binary markers of the nonrecombining Y chromosome (NRY). Ten lineages account for .95% of the 1007 European Y chromosomes studied. Geographic distribution and age estimates of alleles are compatible with two Paleolithic and one Neolithic migratory episode that have contributed to the modern European gene pool. A significant correlation between the NRY haplotype data and principal components based on 95 protein markers was observed, indicating the effectiveness of NRY binary polymorphisms in the characterization of human population composition and history. 

Analyses of mtDNA sequence variation in European populations have been conducted (6, 20). These data suggest that the gene pool has ;80%  Paleolithic and ;20% Neolithic ancestry. Our data support this observation because haplotypes Eu4, Eu9, Eu10, and Eu11 account for ;22% of European Y  chromosomes. Thus, the mtDNA and Y data corroborate the previous observation that the first PC of the 95 classical polymorphisms accounts for ;28% of the overall genetic variation (5, 6). However, some differences exist between the mtDNA and Y data pertaining to the putative Paleolithic components. It has been proposed that mtDNA haplogroup U5 arrived from the Middle East 45,000 years ago (6, 26). We did not detect any corresponding Y haplotypes. Furthermore, most European mtDNA lineages, which account for 60 to 70% of the variation in Europe, have been interpreted as having arrived from the Middle East during the Paleolithic about 25,000 years ago (6). Correspondingly, ;20% of contemporary Y lineages characterized by the M170 mutation derive from deep phylogenetic M89 ancestry, consistent with a Middle Eastern Paleolithic heritage. Moreover, the remaining ;50% of Y lineages associated with the M173 mutation indicate a major influence  on the extant gene pool from Central Asia ;30,000 years ago. In contrast, Central Asian mtDNA 16223/C haplogroups (I, X, and W) account for only ;7% of the contemporary composition (26). These discrepancies may be due in part to the apparent more recent molecular age of Y chromosomes relative to other loci (27), suggesting more rapid replacement of previous Y chromosomes. Gender-based differential migratory demographic behaviors will also influence the observed patterns of mtDNA and Y variation (24).

The previously categorized Sardinians, Basques, and Saami outliers (5) share basically the same Y binary components of the other Europeans. Their peculiar position with respect to frequency is probably a  consequence of genetic drift and isolation. In addition, our analysis highlights the expansion of the Epi-Gravettian population from the northern Balkans. Almost all of the European Y chromosomes analyzed in the present study belong to 10 lineages characterized by simple biallelic mutations. Furthermore, a substantial portion of the European gene pool appears to be of Upper Paleolithic origin, but it was relocated after the end of the LGM, when most of Europe was repopulated.

So the research topic this week is European Y chromosomes. I’ve been having an argument with someone over this, so I’ll be posting a bit on the subject for my own reference.

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