Y chromosome variation in Europe

The well-known Italian geneticist Andrea Noveletto has written an interesting article on the current knowledge about the European Y chromosome distribution. I heartily recommend that you get a copy of this paper which contains lots of useful summarization of previous work with some new interpretations. An excerpt related to Greece:

Greece and Greek Islands


Greece, Crete and the Aegean Islands is a key area to understand the migrations of early farmers to the rest of Europe. A detailed view of the role of Neolithic processes in shaping the Turkish gene pool has been proposed (Cinnioglu et al. 2004). Together with Turkey, Greece and the Aegean appear clearly as a source for haplogroup J2, but the timing for further movements to the west has not yet been fully established. The well documented expansion of the Ancient Greek world, consisting of repeated colonizations, is an immediate candidate process to have spread in the first millennium BC haplogroups that can be dated to an earlier phase of the Neolithic. This punctuation in the dispersal of 'Neolithic' genes has been hypothesized (Malaspina et al. 2001; Di Giacomo et al. 2003) based on haplogroup J, but further phyletic resolution of other haplogroups is needed. The present-day landscape of Greece is also characterized by a small-scale heterogeneity distinct from the continent-wide clines (Figure 2). This potentially provides the possibility of finding haplogroups or STR haplotypes linking the territories of colonies to those of the respective mother cities, as these relationships are historically known.

Greece and Crete also bring the signature of gene flow from north-eastern Europe, mainly represented by frequencies of R1a like nowhere else in southern Europe. This haplogroup is particularly abundant in Thessaly and underwent a further increase in eastern Crete (Di Giacomo et al. 2003).

and on the Carpathians and Balkans:

It is important to observe that, in spite of a bulk geographic continuity with Greece by land, and through the Ionian Sea, populations of this area display relatively low frequencies of lineages within haplogroup J2 (with the exception of J2e), i.e. little input of what are considered typical markers of the Neolithic diffusion or of post-Neolithic movements ensuing it. Conversely, these haplogroups seem to have undergone a more pronounced entry along the eastern edge of the Balkan peninsula and along the Black Sea coasts.

Ann Hum Biol. 2007 Mar-Apr;34(2):139-72.

Y chromosome variation in Europe: Continental and local processes in the formation of the extant gene pool


Andrea Novelletto

Abstract

The polymorphism of the male-specific portion of the Y chromosome has been increasingly used to describe the composition of the European gene pool and to reconstruct its formation. Here the theoretical grounds and the limitations of this approach are presented, together with the different views on debated issues. The emerging picture for the composition of the male gene pool of the continent is illustrated, but local peculiarities that represent departures from the main trends are also highlighted, in order to illustrate the main unifying feature, i.e. the overlay of recent patterns onto more ancient ones. A synopsis of the main findings and conclusions obtained in regional studies has also been compiled.

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