Zack Ajmal has been taking his Reference 3 data set for a stroll over at the Harappa Ancestry Project. Or, more accurately, he’s been driving his computer to crunch up ADMIXTURE results ascending up a later of K’s. Because it is the Harappa Ancestry Project Zack’s populations are overloaded a touch on South Asians. He managed to get a hold of the data set from Reconstructing Indian History. If you will recall this paper showed that the South Asian component which falls out of ancestry structure inference algorithms may actually be a stabilized hybrid of two ancient populations, “Ancestral North Indian” (ANI) and “Ancestral South Indian” (ASI). ANI are a population which can be compared pretty easily to other West Eurasians. There are no “pure” groups of ASI, but the indigenous peoples of the Andaman Islands are the closest, having diverged from the mainland ASI populations tens of thousands of years ago.

At K = 11, that is, 11 inferred ancestral populations, Zack seems to have now stumbled onto the patterns which one would expect from this hybrid model of South Asians. Let me quote him:

Now let’s take all the reference populations with an Onge component between 10% ...