This study is the first study to fully sequence genomes of Neolithic and Mesolithic Europeans, and report Y-chromosome haplogroups from Mesolithic Europe.
Five out of the five successfully tested Mesolithic Y-chromosomes, one from Luxembourg and four from Motala, Sweden, belonged to haplogroup I. This probably won’t come as a surprise to many people, as this haplogroup was always the main candidate for Europe’s Paleolithic paternal marker. Interestingly, three of the results fell into haplogroup I2a1b, and none into the presently locally more common I1.
What this suggests is that I1 expanded after the Mesolithic and replaced most of the I2a1b across Northwestern Europe. I’d say these were mostly expansions from North-Central Europe, although recent chatter on the web suggests that two distinct I1 lineages might have arrived in North-Central Europe from Eastern Europe at different times.
All of the Mesolithic mtDNA sequences belonged to haplgroups U2 and U5, which is line with past results. The single Neolithic sample, from a 7500 year-old Linearbandkeramik (LBK) site in Stuttgart, Germany, belonged to mtDNA haplogroup T2. Again, not very surprising considering what we’ve seen to date.
However, the genome-wide results are not as straightforward. The basic upshot is that Northern Europeans are mostly of indigenous European hunter-gatherer origin, while Southern Europeans are largely derived from Neolithic farmers of mixed European and Near Eastern origin.
But the authors identify a minimum of three ancestral populations from their stats (WHG, EEF and ANE), and four meta-populations from the available ancient data (WHG, EEF, ANE and SHG). Here are a brief summaries of each of these groups: