January 22, 2008

Y chromosomes of Bakhtiari and Arabs from Iran

An interesting observation regarding haplogroups J2 and G in Indo-European and Semitic-speaking Iranians:
Haplogroup J2*(M172) was found in relatively high frequencies in the Iranian Arab and Bakhtiari groups, as well as in other groups from Iran. Haplogroup G* (M201) was found with similar frequency in Iranian Arabs as in the Iranian groups from Tehran and Isfahan, but in higher frequency in the Bakhtiari, as with the Mazandarani and Gilaki groups from Iran (Nasidze et al., 2004, 2006). To further investigate the relationships of these groups based on these two Y-SNP haplogroups, we typed nine Y-STR loci in individuals with these two Y-SNP haplogroups. Median networks of the Y-STR haplotypes are shown in Figure 5. For both Y-SNP haplogroups, the Bakhtiari are more similar to other Iranian groups than to the Iranian Arabs. Moreover, there is very little sharing of Y-STR haplotypes between Iranian Arabs and other groups from Iran, in contrast to the situation with mtDNA HV1 sequences.

This is an interesting observation which is inline with my previous suggestion about the presence of haplogroup J2 in early Indo-Aryan speakers, and which suggests that this haplogroup is not of recent Semitic origin in Iranian speakers.

A quite peculiar conclusion from the paper:
This case adds to our previous studies that have attempted to disentangle the relative influence of geography and language on the genetic relationships of groups whose geographic neighbors are different from their linguistic neighbors. Some general patterns are beginning to emerge from these studies of linguistic enclaves. One pattern is that observed in the present study, namely extensive mixing of groups speaking different languages.

One has to wonder how "extreme mixing" is compatible with "very little sharing of Y-STR haplotypes between Iranian Arabs and other groups from Iran" for Y-haplogroups J2 and G.

Annals of Human Genetics (OnlineEarly Articles).

Close Genetic Relationship Between Semitic-speaking and Indo-European-speaking Groups in Iran

I. Nasidze et al.

As part of a continuing investigation of the extent to which the genetic and linguistic relationships of populations are correlated, we analyzed mtDNA HV1 sequences, eleven Y chromosome bi-allelic markers, and 9 Y-STR loci in two neighboring groups from the southwest of Iran who speak languages belonging to different families: Indo-European-speaking Bakhtiari, and Semitic-speaking Arabs. Both mtDNA and the Y chromosome, showed a close relatedness of these groups with each other and with neighboring geographic groups, irrespective of the language spoken. Moreover, Semitic-speaking North African groups are more distant genetically from Semitic-speaking groups from the Near East and Iran. Thus, geographical proximity better explains genetic relatedness between populations than does linguistic relatedness in this part of the world.


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