The Genetic History of Europe

The combination of forensic archaeology with genetics is making real progress these days, pointing toward a time when it will make a great contribution to our understanding of the past. I don't think we are there yet; the authors of the latest major study on the genetics of the European neolithic wisely put this caveat near the start of their paper:

The genetics of prehistoric populations in Europe remain poorly understood.

This new paper, by Wolfgang Haak and about twenty other people (science!), considers DNA extracted from skeletons found in a cemetery at the German neolithic site of Derenburg Meerenstieg. These people were from the culture archaeologists call the LinerBandKeramik or LBK, the first farmers in central Europe, around 5500-4900 BC. Rather amazingly (to me, anyway) they managed to extract mitochondrial DNA from 17 of the 21 skeletons they examined, and Y chromosome DNA from four. Their results show that the Derenburg Meerenstieg people were more closely related to modern populations in the Middle East, especially central Turkey and Iraq, than they are to modern Europeans.

Results like this argue strongly that farming was brought to Europe by immigrants from the Middle East. The farmers of the European Neolithic were distinct, genetically, from the hunter-gatherers who preceded them. Since this is also the most obvious interpretation of the archaeological data, I think most archaeologists now accept this. The genetic data also support the archaeological data in showing that the wave of Middle Eastern migrants did not reach Scandinavia, but petered out somewhere in the north European plain.

The puzzling thing about the genetic data is what they show about the relationship between ancient and modern Europeans. According to these studies, modern Europeans are not descendants of either Europe's first farmers or Europe's ancient hunter-gatherers. Based on statistical tests, ancient and modern European populations are quite different. Studies of particular lineages of mitochondrial DNA show that some modern Europeans could be descendants of Paleolithic hunter-gatherers, and others could be descendants of those first farmers. But the genetic profiles of the populations are as different as Norwegians are from Syrians. As Haak et al. put it, their data show "that major demographic events continued to take place in Europe after the early Neolithic."

The language they choose is deliberately vague about what those events might be, because this is controversial territory. But given how close this is to modern times the obvious interpretation is that some other large group of people entered Europe after neolithic times. And the obvious candidate for those immigrants would be the people who brought in Indo-European languages. Archaeologists hate this notion, because they can't find any clear evidence for a major invasion in the Bronze Age, but it seems to me that the combination of linguistic and genetic data is starting to overwhelm their objections.