I’ve been rather busy with other things and the South Asian Genotype Project has fallen a bit by the wayside. But, I plan on allocating a day on a weekend soon to getting through the backlog. But, before that, I thought I would submit something that might clarify or illuminate an aspect of South Asian history and culture that the data have shown.
The public data have a large number of Bangladeshis. Sampled in Dhaka. Unlike most South Asians they don’t exhibit much structure. But unfortunately, we don’t have too many samples from West Bengal. That being said, I do get some through this project. As you can see on the plot (round dark point) the Brahmins of Bengal are genetically very distinct from the Bangladesh samples (I have more samples, but this position is always the same for all of them). In fact, they are closer to Brahmin samples from Uttar Pradesh. Using modeled based clustering though I have become strongly convinced that the Bengali Brahmins do have a minor contribution from the non-Brahmin Bengali population because they have East Asian ancestry.
The triangles on the plot are from Kayastha individuals from West Bengal. I have seen a few Kayasthas from this region, and two trends about them: