The most frequent haplotype in a sample of Armenians was seen against the background of HG1 Y chromosomes. It occurred in all Armenian groups, at frequencies ~5-14%. According to YHRD, the same haplotype defined over more loci (14 13 29 24 11 13 12 11,14) was also the most frequent one, occurring in 3% of Armenians (*). According to Whit Athey's haplogroup predictor, this is suggestive of haplogroup R1b. A search for the haplotype in YHRD produced the following result:
The geographical distribution of this haplotype is such that it is shared by Armenians and two other populations from the Caucasus. Moreover, it is lacking in most other populations from the Caucasus, as well as in the other populations from further east. On the other hand, it is more frequently found in Europe, where as we know, haplogroup R1b tends to have higher frequencies as well.
The Armenian modal haplotype is also the modal R1b3 haplotype observed by Cinnioglu in Anatolia. According to him, apparently it entered Anatolia from Europe in Paleolithic times, and diffused again from Anatolia in the Late Upper Paleolithic.
An alternative explanation may be that the particular haplotype may have been associated with the movement of the Phrygians into Asia Minor. The Phrygians were an Indo-European people of the Balkans who settled in Asia Minor, and the Armenians were reputed to be descended from them. It would be interesting to thoroughly study the populations of modern Thrace, Anatolia, and Armenia, and to investigate whether a subgroup of R1b3 chromosomes linked by the Armenian modal haplotype may represent the signature of a back-migration into Asia of Balkan Indo-European peoples.
(*) Since this is an extended haplotype which includes some fast mutating markers, it is expected that it would occur at a lower frequency than the 6-locus haplotype reported by Weale et al.