Close genetic relationship between Semitic-speaking and Indo-European-speaking groups in Iran.

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.

Genetic evidence concerning the origins of South and North Ossetians.

Ossetians are a unique group in the Caucasus, in that they are the only ethnic group found on both the north and south slopes of the Caucasus, and moreover they speak an Indo-European language in contrast to their Caucasian-speaking neighbours. We analyzed mtDNA HV1 sequences, Y chromosome binary genetic markers, and Y chromosome short tandem repeat (Y-STR) variability in three North Ossetian groups and compared these data to published data for two additional North Ossetian groups and for South Ossetians. The mtDNA data suggest a common origin for North and South Ossetians, whereas the Y-haplogroup data indicate that North Ossetians are more similar to other North Caucasian groups, and South Ossetians are more similar to other South Caucasian groups, than to each other. Also, with respect to mtDNA, Ossetians are significantly more similar to Iranian groups than to Caucasian groups. We suggest that a common origin of Ossetians from Iran, followed by subsequent male-mediated migrations from their Caucasian neighbours, is the most likely explanation for these results. Thus, genetic studies of such complex and multiple migrations as the Ossetians can provide additional insights into the circumstances surrounding such migrations.

Mitochondrial DNA and Y-chromosome variation in the caucasus.

We have analyzed mtDNA HVI sequences and Y chromosome haplogroups based on 11 binary markers in 371 individuals, from 11 populations in the Caucasus and the neighbouring countries of Turkey and Iran. Y chromosome haplogroup diversity in the Caucasus was almost as high as in Central Asia and the Near East, and significantly higher than in Europe. More than 27% of the variance in Y-haplogroups can be attributed to differences between populations, whereas mtDNA showed much lower heterogeneity between populations (less then 5%), suggesting a strong influence of patrilocal social structure. Several groups from the highland region of the Caucasus exhibited low diversity and high differentiation for either or both genetic systems, reflecting enhanced genetic drift in these small, isolated populations. Overall, the Caucasus groups showed greater similarity with West Asian than with European groups for both genetic systems, although this similarity was much more pronounced for the Y chromosome than for mtDNA, suggesting that male-mediated migrations from West Asia have influenced the genetic structure of Caucasus populations.