The extent and nature of southeastern Europe (SEE) paternal genetic contribution to the European genetic landscape were explored based on a high-resolution Y chromosome analysis involving 681 males from seven populations in the region. Paternal lineages present in SEE were compared with previously published data from 81 western Eurasian populations and 5,017 Y chromosome samples. The finding that five major haplogroups (E3b1, I1b* (xM26), J2, R1a, and R1b) comprise more than 70% of SEE total genetic variation is consistent with the typical European Y chromosome gene pool. However, distribution of major Y chromosomal lineages and estimated expansion signals clarify the specific role of this region in structuring of European, and particularly Slavic, paternal genetic heritage. Contemporary Slavic paternal gene pool, mostly characterized by the predominance of R1a and I1b* (xM26) and scarcity of E3b1 lineages, is a result of two major prehistoric gene flows with opposite directions: the post-Last Glacial Maximum R1a expansion from east to west, the Younger Dryas-Holocene I1b* (xM26) diffusion out of SEE in addition to subsequent R1a and I1b* (xM26) putative gene flows between eastern Europe and SEE, and a rather weak extent of E3b1 diffusion toward regions nowadays occupied by Slavic-speaking populations.

SummaryThe Balkan Peninsula is a complex cultural mosaic comprising populations speaking languages from several branches of the Indo-European family and Altaic, as well as culturally-defined minorities such as the Aromuns who speak a Romance language. The current cultural and linguistic landscape is a palimpsest in which different peoples have contributed their cultures in a historical succession. We have sought to find any evidence of genetic stratification related to those cultural layers by typing both mtDNA and Y chromosomes, in Albanians, Romanians, Macedonians, Greeks, and five Aromun populations. We have paid special attention to the Aromuns, and sought to test genetically various hypotheses on their origins.MtDNA and Y-chromosome haplogroup frequencies in the Balkans were found to be similar to those elsewhere in Europe. MtDNA sequences and Y-chromosome STR haplotypes revealed decreased variation in some Aromun populations. Variation within Aromun populations was the primary source of genetic differentiation. Y-chromosome haplotypes tended to be shared across Aromuns, but not across non-Aromun populations. These results point to a possible common origin of the Aromuns, with drift acting to differentiate the separate Aromun communities. The homogeneity of Balkan populations prevented testing for the origin of the Aromuns, although a significant Roman contribution can be ruled out.

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SummaryWe have analysed 11 human-specific Alu insertion polymorphisms in the Balkans to elucidate the origins of the Aromuns, a linguistic isolate inhabiting scattered areas in the Balkan Peninsula. Four Aromun samples (two from the Republic of Macedonia, one from Albania, and one from Romania) and five neighbouring populations (Macedonians, Albanians, Romanians, Greeks, and Turks) were analysed by means of genetic distances, principal components and analyses of the molecular variance (AMOVA). Three hypotheses were tested: Aromuns are Romanophonic Greeks; the result of a Romanian southward migration; or local descendants of the Thracians. The analyses show that the Aromuns do not constitute a homogeneous group separated from the rest of the Balkan populations. Grouping by language or geography does not explain the genetic differences observed in the region, suggesting a lack of genetic structure in the area. Aromuns do not seem to be particularly related to Greeks, Romanians, or to other Romance speakers. The Aromuns might have their origin to the south of the Danube river, with extensive gene flow with the neighbouring populations. The present results suggest a common ancestry of all Balkan populations, including Aromuns, with a lack of correlation between genetic differentiation and language or ethnicity, stressing that no major migration barriers have existed in the making of the complex Balkan human puzzle.