Harvard's David Reich is doing a talk next month about the genetic history of West Asia and nearby parts of Europe. This is a quote from an online abstract of the talk (found
here).
The impermeability of Anatolia to exogenous migration contrasts with our finding that the Yamnaya had two distinct gene flows, both from West Asia, suggesting that the Indo-Anatolian language family originated in the eastern wing of the Southern Arc and that the steppe served only as a secondary staging area of Indo-European language dispersal.
If this is actually what David Reich is going to claim then I'd say his team has a lot of work to do before they put out their paper on the topic.
First of all, Yamnaya did not have two distinct gene flows from West Asia. I don't even know what that means exactly, but there's no way that this statement is correct no matter how one interprets it.
In fact, the Yamnaya population formed on the Pontic-Caspian steppe from earlier groups native to this part of Eastern Europe, such as the people associated with the Sredny Stog culture.
That is, there were no migrations from West Asia into Eastern Europe that can be claimed to have been instrumental in the emergence of the Yamnaya population. On the other hand, Yamnaya may have been significantly influenced by cultural impulses from West Asia, but this is nothing new.
In terms of
deep population structure, the Yamnaya genotype can be described as a mixture between Eastern European and West Asian-related genetic components. However, these Asian-related components were already in Europe thousands of years before Yamnaya came into existence.
Indeed, soon to be published ancient DNA shows that hunter-gatherers very similar to the Yamnaya people, packing quite a lot of West Asian-related ancestry, lived in the Middle Don region (just north of the Pontic-Caspian steppe) well before 5,000 BCE (see here).
So, did the West Asian ancestors of these Middle Don hunter-gatherers speak Proto-Indo-European, or, as David Reich calls it, Indo-Anatolian? Keep in mind that most linguists put the birth of Indo-Anatolian around 4,000 BCE, which is actually the Sredny Stog period.
Moreover, in underlining Anatolia's supposed impermeability to exogenous migration, David Reich is arguing against things that no one worth their salt ever claimed. That's because the spread of Indo-Anatolian speakers into Anatolia has never really been described by archeologists and linguists as a massive migration, but rather as an infiltration into lands already heavily populated by the Hattians (for instance, see
here).
We may have already seen the genetic evidence of this infiltration in the presence of steppe Y-chromosome haplogroup R-V1636 in a Chalcolithic burial at Arslantepe (see
here and
here). Let's wait and see what else crops up over the next few years as many more ancient Anatolian genomes are sequenced by David Reich and colleagues.
See also...
