Since David hasn’t mentioned it, I’m going to post some notes on Dynamic changes in genomic and social structures in third millennium BCE central Europe. This is a big deal because there’s a huge data-set spanning the Neolithic (older than 3000 BC) to the Bronze Age in Bohemia, looking at Globular Amphora, Corded Ware, Bell Beaker, and Únětice. Since I’m not too familiar with European archaeology, the most surprising thing that jumped out at me is that there was structure and variability in the nature and origins of the Neolithic societies in the region. The Bohemian Funnel Beaker populations seem to have been migrants from the west, for example.
The two big takeaways:
- Confirms serial admixture that tends to be female-mediated from Neolithic (though some “pure” steppe women also migrated)
- The Corded Ware and successor cultures in the region seem to have an affinity for an unsampled population to the north of the Yamnaya zone, in the forest-steppe
The first part is highlighted by the fact that several individuals with ~0% steppe ancestry are buried early on as “Corded Ware.” These were clearly individuals who were culturally assimilated, but their ancestry was totally different. Some of these women in particular seem to have been non-local as well, though from Neolithic societies. This suggests, unsurprisingly, that the ethnogenesis of Indo-European cultures was synthetic and complex. The figure to the top/right illustrates the trend whereby the earliest Corded Ware population exhibited far greater genetic distances between individuals than is to be found in modern European pairwise comparisons. This is part of the broader trend that over the recent past there’s been a massive worldwide panmixia.
Second, the Corded Ware has always been an awkward fit with a simple Yamnaya+Neolithic admixture. The stylized model, which I’ve repeated for simplicity, is that the Yamnaya moved west and mixed with the locals. Kristian Kristiansen explicitly refers to the Corded Ware as basically Yamnaya when I pushed him on this, and who am I to disagree with him? I think the key distinction here is that archaeologically the Corded Ware seems so much like European adaptations of the Yamnaya cultural toolkit…but genetically there are subtle indications of difference. Basically, the authors argue, plausibly, that the Corded Ware is not derived from the Yamnaya as such (their Y chromosomes do not match anyway), but a Yamnaya-adjacent population in the forest-steppe. This region seems to have also contributed a second pulse of migration which resulted in increased northeastern affinity, and a higher fraction of R1a lineages.
When it comes to the Y chromosomes, the authors conclude that inter-group competition was intense, and resulted in serial replacements of paternal lineages. The reproductive fitness gain they estimate for the elite lineages is 15% per generation, which is a very large number in evolutionary genetics (2% selection coefficients are large in this field). The Bell Beaker group seems to have been reflux from the west, and it itself was replaced later on by the Únětice.
One of the less supported, though still useful, models for the Corded Ware is a genetic influx from Pitted Ware samples, the mostly “EHG” hunter-gatherer group from Sweden. I think this supports the proportion that a group of early Yamnaya penetrated the forest-steppe, and assimilated hunter-gatherers in the southern portions of the taiga. If my read of the archaeology is correct, the overwhelmingly dominant culture of these synthetic groups was Yamnaya-like.
Finally, I have to wonder about these peoples’ association with and relationship to the Fatyanovo culture of western Russia, right in the forest-steppe. These groups seem to have been proto-Indo-Iranian judging by their R1a1a-Z93. One of the individuals in these data was clearly Z282, which is so common among Slavs (and Europe).