Quote Originally Posted by Maciamo View Post
R1a-M417 is much younger (TMRCA of 5500 years, at the start of Yamna) than R1b-M269 or even R1b-L23. Considering that all Indo-European R1a descends from a single R1a-M417 who lived at the beginning of the Yamna period, I don't see how R1a-M417 could be found alongside R1b-M269 in the South Caucasus. It was clearly an indigenous R1a lineage that got lucky, probably becoming a prolific chieftain or king in the forest-steppe zone that gave rise to Corded Ware. Yamna individuals tested were mostly from elite graves, but there is little doubt in my mind that the 'common people' were the same as in Sredny Stog (old clades of R1a and R1b + I2a2a-L701). It's thanks to elitism, patriarchy and polygamy that R1b-Z2103, R1b-L51 and R1a-M417 managed to expand so very fast at the expense of now nearly extinct side lineages of R1a and R1b.
I would say J2b2-L283 probably expanded in the same manner as those 3 Hg's you just mentioned, just in the direction of balkan, instead of in the direction of northern Europe.
If they were not one of the elite lineages too, then it does not make sense why J-L283 and R-Z2103 got to colonize the best and most fertile areas with the most lootable stuff, while L51 and M417 got the more desolate and mineral-poor north.