January 26, 2014
Brown-skinned, blue-eyed, Y-haplogroup C-bearing European hunter-gatherer from Spain (Olalde et al. 2014)
The new study La Brana 1 identifies it as ancestral in the SLC24A5 locus in which virtually all Europeans are derived. This comes in the heels of the Loschbour preprint which identified that sample from Luxembourg as also being ancestral. Taken together, it's now clear that hunter-gatherers from Mesolithic Western Europe were brown.
Curiously, it now seems that both Europe and India were (in part) inhabited by brown people and became lighter by a process of admixture + selection. The process went "all the way" in Europe, but a cline of pigmentation was sustained in India.
The other finding (not mentioned in the abstract) is that La Brana 1 belonged to Y-haplogroup C6! This is a low-frequency European clade of haplogroup C. So now, we have evidence that haplogroup C is not eastern Eurasian (as the presence of its subclades in Australia, India, East Asia, and the Americas might suggest), but a pan-Eurasian entity. It remains to be seen whether this C-in-Europe can be pushed further back in time, but finding it in Mesolithic Iberia reduces the chance that it's some random eastern Eurasian who made it to the outskirts of Europe recently.
Finally, La Brana 1 has derived alleles at loci associated with pathogen resistance. This might be important, because a common hypothesis is that Europeans developed this type of resistance during the Neolithic as they started interacting with the pathogens of domesticated species and started living in less-hygienic higher-density settlements.
Nature (2014) doi:10.1038/nature12960
Derived immune and ancestral pigmentation alleles in a 7,000-year-old Mesolithic European
Iñigo Olalde et al.
Ancient genomic sequences have started to reveal the origin and the demographic impact of farmers from the Neolithic period spreading into Europe1, 2, 3. The adoption of farming, stock breeding and sedentary societies during the Neolithic may have resulted in adaptive changes in genes associated with immunity and diet4. However, the limited data available from earlier hunter-gatherers preclude an understanding of the selective processes associated with this crucial transition to agriculture in recent human evolution. Here we sequence an approximately 7,000-year-old Mesolithic skeleton discovered at the La Braña-Arintero site in León, Spain, to retrieve a complete pre-agricultural European human genome. Analysis of this genome in the context of other ancient samples suggests the existence of a common ancient genomic signature across western and central Eurasia from the Upper Paleolithic to the Mesolithic. The La Braña individual carries ancestral alleles in several skin pigmentation genes, suggesting that the light skin of modern Europeans was not yet ubiquitous in Mesolithic times. Moreover, we provide evidence that a significant number of derived, putatively adaptive variants associated with pathogen resistance in modern Europeans were already present in this hunter-gatherer.