Genetics and Migration in Neolithic Europe

A new paper in Science by Guido Brandt et al. examines the mitochondrial DNA from 364 Neolithic skeletons to consider how the population of central Europe changed. Dienekes summarizes:

researchers compiled mtDNA results from 364 prehistoric central Europeans from the early Neolithic to the early Bronze Age, spanning about four millennia of history. Importantly they uncover not a smooth transition between early Neolithic farmers and modern Europeans, but a punctuated series of haplogroup frequency changes that cannot really be explained by genetic drift in a single European population evolving over time. Hopefully this kind of research can be repeated in other parts of the world, as it provides a way to see evolution and migration as it happens. Earlier work has disproved the hypothesis that modern Europeans are simply "acculturated" hunter-gatherers, and this newer research disproves the idea that they are simply the descendants of early farmers, little modified since the beginning of the Neolithic.

Given the complexity of the pattern, this is not a very big sample, but the results are still fascinating. When farmers first arrived from the Middle East, the genes of native hunter gatherers (the gray line) disappeared; but then they came back after 3400 BCE. The authors suggest migration from Scandinavia, which never saw much Middle Eastern migration, back into central Europe.

And then after 3000 BCE entirely new groups arrive, shown by the yellow line. These might be the speakers of Indo-European languages, entering from the steppes; or on the other hand they might have come via Spain. The authors supply the maps above for their four "events": the arrival of Middle Eastern farmers; the migration of Scandinavians, a mixed population, back to central Europe; and migrations into central Europe from Spain and the steppes. At any rate it is clear that the population history of Europe is complicated, and requires that people have done a lot of moving around.