One of the things that happens if you read ethnographically thick books like Nicholas Dirks' Castes of Mind: Colonialism and the Making of Modern India is that you start to wonder if most castes were simply created by the British and for the British. Granted, even Dirks would not deny the existence of Brahmins prior to the British period, but those who work within his general paradigm might argue that a group like Kayasthas were the product of very recent developments (e.g., the uplift of a non-Brahmin literate group willing to serve Muslim and British rulers). The emergence of genomics complicates this sort narrative, because you can examine relationships and see how plausible they would be given a particular social model. Zack Ajmal is now at 90 participants in the Harappa Ancestry Project. He's still undersampling people from the Indo-Gangetic plain between Punjab and Bengal, but that's not his fault. Hopefully that will change. He posted K = 4 recently for the last 10 participants, but I notice K = 12 in his spreadsheets. So this is what I did: 1) I aligned the ethnic identification information with the K = 12 results. 2) I removed relatives and those who were not 100% South Asian. 3) I added some reference populations in. These are all upper case below. All other rows are individuals (HRP numbers provided). 4) I removed five ancestral groups. The three Africans, Papuans, and Siberians. Then I arranged the rows alphabetically by ethnic identification. Helpfully many people provided their caste information as well. I've uploaded a csv with the information. But skim the plots & table below. Those of you who are brown can probably make more sense of them than I can. But I think some of the patterns are pretty interesting already. For me the big thing that jumps out is how uniform some of these caste groups are. Remember that HRP22 and HRP23 are my parents. If the British made these groups up, they were very punctilious about their ancestral make up in constituting them! First, this is the visualization of the genetic distance between the groups below:
Most South Asians in the Harappa Ancestry Project are S Asian + Baloch/Caucasian + European. In that order. But there are some weird patterns which other genome bloggers have already noted, but I thought would be nice to reiterate with Zack's larger data set.
