September 12, 2011

Terai and Duars Y-chromosomes

I had not even heard of these populations until today; hopefully South Asian experts elsewhere in the blogosphere will chime in.

J Hum Genet. 2011 Sep 8. doi: 10.1038/jhg.2011.98. [Epub ahead of print]

Y-chromosome haplogroup diversity in the sub-Himalayan Terai and Duars populations of East India.

Debnath M, Palanichamy MG, Mitra B, Jin JQ, Chaudhuri TK, Zhang YP.

The sub-Himalayan Terai and Duars, the important outermost zones comprising the plains of East India, are known as the reservoirs of ethnic diversity. Analysis of the paternal genetic diversity of the populations inhabiting these regions and their genetic relationships with adjacent Himalayan and other Asian populations has not been addressed empirically. In the present investigation, we undertook a Y-chromosome phylogeographic study on 10 populations (n=375) representing four different linguistic groups from the sub-Himalayan Terai and Duars regions of East India. The high-resolution analysis of Y-chromosome haplogroup variations based on 76 binary markers revealed that the sub-Himalayan paternal gene pool is extremely heterogeneous. Three major haplogroups, namely H, O and R, are shared across the four linguistic groups. The Indo-European-speaking castes exhibit more haplogroup diversity than the tribal groups. The findings of the present investigation suggest that the sub-Himalayan gene pools have received predominant Southeast Asian contribution. In addition, the presence of Northeast and South Asian signatures illustrate multiple events of population migrations as well as extensive genetic admixture amongst the linguistic groups.


Andrew Oh-Willeke said...

Normally H would be considered indigenous South Asian, O would be Southeast Asian or East Asian, and R would be West Asian.

Terai is a geographic rather than ethnic designation that includes multiethnic parts of India and Nepal and was traditionally a malaria infested swamp forest (I would make an analogy to rural Louisiana but cooler due to elevation). Duras (aka Dooars) is the ecological continuation of this geographic multiethnic region between Bengal and Bhutan and includes Darjeeling after which the tea is named.

Ethnically it is very complex and only getting more so as modernization has made it possible for new ethnic groups to move in and forces like Lutheran missionaries have changed the cultural landscape.

eurologist said...

The spread of O3a3c1-M117 is just amazing (see also the Cai et al. paper above). It looks like it truly may have wiped out much of the original D in the region.

However, to make sense of the migration patterns, one would need to identify much finer subgroups. Just because O seems ancestral in SE Asia doesn't mean that O3a3c1-M117 indicates the typically assumed counter-clockwise migration pattern. It seems to me more associated with recent rice farming, no?

mregdna said...

Terai is the birthplace of Shakyamuni Buddha. Some historians believed that His clan the Shakyas or Sakkas came from the indo-iranian Sakas. R1a was maybe the haplogroup of Buddha.

terryt said...

"It seems to me more associated with recent rice farming, no?"

I would think so.