Wednesday, July 22, 2015
High-res R1b tree featuring 16 ancient sequences
Here's a useful R1b phylogenetic tree that was posted recently at the R1b-M269 (P312- U106-) DNA Project site.
If these results are correct (and judging by the quality of work at the aforementioned R1b project, I'm pretty sure they are), it would appear that the Samara hunter-gatherer, marked I0124, was not directly ancestral or even all that closely related to any of the Yamnaya/Pit-Grave samples from the North Caspian region (each one also marked with an I~ ID).
On the other hand, the North Caspian Yamnaya sequences are very similar to the rest of the Yamnaya sequences, which come from just north of the Caucasus (marked RISE~). Indeed, all of these Yamnaya samples are almost identical in terms of genome-wide genetic structure (see here).
What this suggests is that the Yamnaya nomads emigrated to the North Caspian from somewhere near the Caucasus, or they were the descendents of such migrants. And if we assume that their ancestral homeland abutted the territory of the Maikop Culture, as shown on this map from Dolukhanov 2014 (look for 9 - early Pit-graves), it becomes easy to understand why they carried such significant maternal and genome-wide genetic Caucasus-related admixture (usually estimated at around 50%).
However, if you're one of those online Near Eastern patriots who like to imagine the Yamnaya as your own, please don't jump for joy just yet. The Yamnaya nomads still look very much like a people native to the western steppe, and this is probably also where their R1b comes from.