A huge surprise of the new @EadaoinSays et al. paper on Chalcolithic Levant is that the OCA2/s12913832 "blue eye" allele frequency is ~1/2, i.e., Chalcolithic Levantines were probably more blue-eyed than Bronze Age people from Russia, a complete inversion of what is now observed.
Mass migration clearly played a part, although Levantines were almost surely not a source for Russian and Ukrainian populations based upon other genetic indicators.
More Twitter discussion here. The abstract of the paper based on ancient DNA results explains that:
The material culture of the Late Chalcolithic period in the southern Levant (4500–3900/3800 BCE) is qualitatively distinct from previous and subsequent periods.
Here, to test the hypothesis that the advent and decline of this culture was influenced by movements of people, we generated genome-wide ancient DNA from 22 individuals from Peqi’in Cave, Israel. These individuals were part of a homogeneous population that can be modeled as deriving ~57% of its ancestry from groups related to those of the local Levant Neolithic, ~17% from groups related to those of the Iran Chalcolithic, and ~26% from groups related to those of the Anatolian Neolithic.
Modern Peq'in in Israel (near the Lebanese-Israeli border) is predominantly Druze in ethnicity, but are almost surely not descendants of the Chalcolithic residents of the area.The Peqi’in population also appears to have contributed differently to later Bronze Age groups, one of which we show cannot plausibly have descended from the same population as that of Peqi’in Cave. These results provide an example of how population movements propelled cultural changes in the deep past.