In this report we reexamine the genetic origins of the Brahuis, and compare them with diverse populations from India, including several Dravidian-speaking groups, and present a genetic perspective on ethnolinguistic groups in present-day Pakistan. Given the high affinity of Brahui to the other Indo-European Pakistani populations and the absence of population admixture with any of the examined Indian Dravidian groups, we conclude that Brahui are an example of cultural (linguistic) retention following a major population replacement.
It was clear 10 years ago when I looked at the HGDP Brahui that they are no different from the HGDP Baloch. This is important because there is as a hypothesis that these Dravidian speakers are migrants from peninsular India. If so, there is no genetic evidence. Admixture must have resulted in total homogenization with the Baloch. This is frankly not plausible for a South Asian group, which tends toward structure.
The second option is that the Brahui Dravidian language is indigenous to the region, and the genetic similar to the Baloch is due to the latter’s reciprocal admixture with the Brahui