Strontium isotopes document greater human mobility at the start of the Balkan Neolithic
Dušan Borić and T. Douglas Price
Questions about how farming and the Neolithic way of life spread across Europe have been hotly debated topics in archaeology for decades. For a very long time, two models have dominated the discussion: migrations of farming groups from southwestern Asia versus diffusion of domesticates and new ideas through the existing networks of local forager populations. New strontium isotope data from the Danube Gorges in the north-central Balkans, an area characterized by a rich burial record spanning the Mesolithic–Neolithic transition, show a significant increase in nonlocal individuals from ∼6200 calibrated B.C., with several waves of migrants into this region. These results are further enhanced by dietary evidence based on carbon and nitrogen isotopes and an increasingly high chronological resolution obtained on a large sample of directly dated individuals. This dataset provides robust evidence for a brief period of coexistence between indigenous groups and early farmers before farming communities absorbed the foragers completely in the first half of the sixth millennium B.C.
The strontium isotype analysis of human skeletal remains provides an independent confirmation of the genetic evidence (including ancient DNA evidence) tending to show that farming came to Europe with mass migrations of farming populations, rather than primarily through technology transfers to existing hunter-gather populations.
Within seven hundred years of their arrival (the press release suggests more like a couple of hundred years), the indigeneous hunter-gather populations of the region were exiled, had died off, or were assimilated in the farming communities.
Neither the press release, nor the abstract set forth above, quantify the extent to which indigeneous hunter-gathering populations of the Balkans were assimilated into farming communities as opposed to being exiled or dying off (a variety of scenarios from genocide to declining game habits that reduce carrying capacity are possible within that category).
We can infer from lines of evidence not included in this study that women were probably more likely to be assimilated into the farming communities than men - leading to greater conservation of mtDNA lineages than Y-DNA lineages across the Mesolithic-Neolithic transition. This study shows a gender differential that is somewhat different although the phrasing could be more clear:
An interesting finding of the study is that 8,000 years ago, when Neolithic farmers were beginning to migrate into the Danube Gorges and overlap with Mesolithic hunter-gatherers, more women than men were identified as foreigners. A possible explanation for the variance, according to the study, is that women came to these sites from Neolithic farming communities as part of an ongoing social exchange.As I read this, the researchers seem to intepret their findings as showing that young male farmers born on the Neolithic frontier (and hence having "local" strontium isotypes) procured wives from more settled Neolithic lands who appeared to be "foreigners" in their strontium isotypes, rather than seeing this as evidence of indigneous men transitioning to farming and then taking Neolithic culture women as wives.