January 31, 2007

Y chromosomes from Lasithi (Crete)

A new paper has appeared about Y chromosome haplogroups in Crete. I will read it more carefully and comment later on. I would be interested in hearing if there are any traditions about the people from Lasithi, which could be correlated with the genetic evidence. Also, I do not have Poulianos' "Origins of the Cretans" books handy, which covers quite extensively the physical anthropology of Crete, so feel free to leave a comment with any relevant information.

A first comment based on a reading of the abstract would be that the similarity between R1b chromosomes from Lasithi and NE Italy could be a legacy of the Venetian period of Cretan history.

UPDATE 1: Absence of non-Caucasoid influences in Lasithi and Heraklion.

There is an absence of Sub-Saharan Y chromosomes (A, B, or E*(xE3b)) in Lasithi and Herakleio. Mongoloid Y chromosomes are also absent. These would be represented by haplogroups C, N, and O. C was typed directly, and the absence of N and O can be inferred from the absence of K* chromosomes using the markers tested. The only chromosomes that could be of non-Caucasoid origin are 2 Q chromosomes, which are more typical of Siberian and Native American populations, although they have been detected in trace amounts in the Middle East and Europe. It remains to be seen whether or not these Q chromosomes represent prehistoric remnants or more recent arrivals from Asia.

UPDATE 2: Limited occurrence of J1 signifies absence of significant Arab influences in Lasithi and Heraklion.

Arab and other Semitic populations usually possess an excess of J1 Y chromosomes compared to other populations harboring Y-haplogroup J. As I have noted elsewhere the predominance of J2 over J1 is typical of European populations of J. In the Cretan samples there are 65 J2 chromosomes and 3 J1 chromosomes. It should be noted that these may not necessarily be of Arab or Semitic origin, since J1 is also found at some frequency in the northern parts of the Middle East inhabited by Caucasian and Iranic speakers and may have been present in early Neolithic times. In any case, the preponderance of J2 over J1 and low occurrence of J1 suggests that the Arab rule of Crete had little effect in terms of characteristically Arab Y chromosomes.

European Journal of Human Genetics advance online publication 31 January 2007

Paleolithic Y-haplogroup heritage predominates in a Cretan highland plateau

Laisel Martinez1, Peter A Underhill2, Lev A Zhivotovsky3, Tenzin Gayden1, Nicholas K Moschonas4, Cheryl-Emiliane T Chow2, Simon Conti2, Elisabetta Mamolini5, L Luca Cavalli-Sforza2 and Rene J Herrera1


The island of Crete, credited by some historical scholars as a central crucible of western civilization, has been under continuous archeological investigation since the second half of the nineteenth century. In the present work, the geographic stratification of the contemporary Cretan Y-chromosome gene pool was assessed by high-resolution haplotyping to investigate the potential imprints of past colonization episodes and the population substructure. In addition to analyzing the possible geographic origins of Y-chromosome lineages in relatively accessible areas of the island, this study includes samples from the isolated interior of the Lasithi Plateau – a mountain plain located in eastern Crete. The potential significance of the results from the latter region is underscored by the possibility that this region was used as a Minoan refugium. Comparisons of Y-haplogroup frequencies among three Cretan populations as well as with published data from additional Mediterranean locations revealed significant differences in the frequency distributions of Y-chromosome haplogroups within the island. The most outstanding differences were observed in haplogroups J2 and R1, with the predominance of haplogroup R lineages in the Lasithi Plateau and of haplogroup J lineages in the more accessible regions of the island. Y-STR-based analyses demonstrated the close affinity that R1a1 chromosomes from the Lasithi Plateau shared with those from the Balkans, but not with those from lowland eastern Crete. In contrast, Cretan R1b microsatellite-defined haplotypes displayed more resemblance to those from Northeast Italy than to those from Turkey and the Balkans.


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