I have talked about the issue of the Brahui before at HAP. A commenter brings up linguistic arguments as to why the Brahui are recent South Indian transplants. That is fine, I can not speak to linguistics. But the genetic evidence strongly would suggest we be skeptical of this position. This does not entail that the genetic evidence is the only line of argument we should weight, but it speaks to the problem of resting our inference on one methodological leg.
- The Brahui and Baloch are indistinguishable in the HGDP data set
- The Brahui, like the Baloch, are one of the least “South Asian” populations in South Asia, insofar as they are genetically well integrated in the landscape of West Asia
- The Brahui have not been Indo-Aryanized, they have been Iranized, if they are South Indian transplants. The distinction is important, because the Brahui tend of exhibit very low level of indigenous South Asian ancestry which is distinctive from West Eurasian (i.e., “Ancestral South Indian”), even compared to groups such as the Pathans. Additionally, they are also clearly influenced by Southwest Asia elements to a greater extent than Pathans and northwest Indians.
If the hypothesis that the Brahui are South Indian is correct they exhibit 100% elimination of South Indian genetic distinctiveness. In this way they may be analogous to the Romany people, but the Romany as a whole exhibit clear signatures of South Asian ancestry, despite heavy admixture with other populations.
Finally, the commenter brings up the issue of representativeness in the Brahui samples. In other words, the “Brahui” sampled by the HGDP were only recently assimilated Baloch into the Brahui tribal grouping. I judge that this issue is actually more likely than the hypothesis that the Brahui South Indian genetic distinctiveness was totally eliminated.