Originally posted by Polako alias David Kowalski at Polish Genetics and Anthropology Blog.
Nature has just published a very interesting article on the discovery of a new type of R1a1a, defined by the M458 marker. The data included in the report firmly puts present day Poland in the driving seat as the place of origin for this lineage, known as R1a1a7. Here’s a nice map…
Peter A Underhill et al., Separating the post-Glacial coancestry of European and Asian Y chromosomes within haplogroup R1a, European Journal of Human Genetics advance online publication 4 November 2009; doi: 10.1038/ejhg.2009.194
However, as per above, the authors claim that R1a1a7 has an age of about 10.7KY. This, they say, makes it a signal of migrations carrying agriculture from Central-East Europe to present day Ukraine and European Russia. Unfortunately, that doesn’t make any sense, because M458 is very rare in Scandinavia, which was largely populated from North/Central Europe after the Ice Age. Recent work on the population movements around the Baltic have shown that both R1a1 and I1a moved up from Germany and Poland into Sweden. So why was only one case of M458 discovered up there in this study?
T. Lappalainen et al., Migration Waves to the Baltic Sea Region, Annals of Human Genetics, Volume 72 Issue 3, Pages 337 – 348, doi: 10.1111/j.1469-1809.2007.00429.x
My take on what’s happened here is that the authors grossly overestimated the age of M458, by about three times. The real figure is probably somewhere between 3 and 4KY. So it’s pretty obvious what we’re dealing with here are the various migrations of Slavs around Central and Eastern Europe, probably starting in the upper Vistula basin. These population movements took place well AFTER previous waves of R1a1 moved north and west from or via present day Poland.
Based on their inflated age and expansion time estimates for M458, the authors also conclude that it’s unlikely there were any major post-Ice Age movements from Eastern Europe to Asia. This implies they trust their own methodology more than the recent results of ancient DNA studies, which clearly showed that European groups carrying R1a1 migrated in a big way to South Siberia during the Chalcolithic and Bronze Age (see here). Indeed, the west to east movements of these Scytho-Siberians were also tracked by a recent cranial study of their remains (here). So well done on finding the new R1a1 marker, but geez, there’s something not quite right there with those haplogroup age estimates again. When will that change I wonder?