Ol’ Blue-Eyes

A grave has been found near Leon in Spain containing a 7,000 years old Neolithic human skeleton. By some amazing good luck some of the bones contain DNA , and this shows the genes associated with the immunity and diet needed for a shift from hunting to agriculture.

But there’s little data from other earlier hunter-gatherers to be sure of what changes took place at the transition from hunting animals to growing crops. Nevertheless, these 7,000 year old Spanish fossils give a complete  pre-agricultural European human genome.

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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. DNA from the Spanish fossils have several skin pigmentation genes, suggesting that the light skin of modern Europeans was not established. But the same pathogen resistance found in modern Europeans was already present in this hunter-gatherer.

Before the Neolithic changes human’s eyes were brown, but a mutation caused a fall in melanin synthesis needed to make eyes brown. The mutation may have arisen in a single individual probably living in the northwestern part of the Black Sea region 6,000–10,000 years ago. With less melanin, eyes became blue

In Estonia, 99% of people have blue eyes,” says Hans Eiberg from the Department of Cellular and Molecular Medicine at Copenhagen. They are also common around the Baltic Sea, in Germany and Israel. 

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DNA studies of Bronze and Iron age fossils in the Siberian Krasnoyarsk region also show melanin deficiency, which means they must have had blue eyes. There was this same deficiency in the Leon specimens from Spain, the 7,000 year old hunter-getherers, who also had brown skin and dark hair. That hair’s another story.