In a comment below I alluded to my idea that
the heart of Eurasia was relatively unpopulated before the Holocene
, explaining why many Central Asian groups seem to be recent hybrids from very distinct populations. Normally the sort of model which posits K ancestral groups is an idealization to some extent. To assign every K to a real known ancient population is probably not tenable in most cases. Not so for many Central Asian groups, for the K's often seem rather clear and distinct, and we have a fair amount of historical pointers. Thanks to Herodotus, the early Han dynasty chroniclers, and the Avesta, we have some sense of what the ethnography of Central Asia was like several thousand years ago. Additionally, it seems possible that highly advanced societies such as that of Bactria-Margiana were transferred from elsewhere. The heart of Eurasia may have been to a great extent ...
