About 35,000 years ago, in Buran-Kayato the north of the mountains of Crimea, the first person who knows that he had blue eyes died. Since then, the story of the Iris clear has been complex, violent and very interesting.
Today, thanks to the improvement of genetic analysis techniques, we know many things. In recent years, it has been said that effectively The Vikings had blue eyesthat the eyes of the steppe peoples were surprisingly dark and that, during the Roman Empire, the clear eyes almost disappeared.
How do we know all this? Davide Piffer used 4,133 old genomes (They covered 44,000 years) to explain when the blue eyes arose, how they were selected generation after generation and why today there are people who still have them.
Why do we have blue eyes? At the genetic level, which is what interests us in this case, the explanation is simple: As Piffer himself explained“Blue eyes genetics focuses on two neighboring genes on chromosome 15: OCA2 that controls the production of melanin in the iris, and Herc2 which contains a regulatory element “.
In the case of brown eyes, “Herc2 ‘active’ OCA2 effectively to produce enough pigment.” With blue eyes, the situation is different: a mutation in RS12913832 weakens HERC2 control and the least amount of melanin is perceived as bluish or greenish eyes.
That is, there is a genetic ‘trace’ that allows us to dive in ancient DNA to know how (with a certain degree of variability) the eyes of our ancestors.
What did you discover? This is how Piffer confirmed That the Vikings had mostly blue eyes, the steppe peoples had them darker than expected and that the current prevalence of clear eyes is due to fairly recent factors. He also discovered something curious: that the story of Rome is much more complicated than it seems.
While in ancient Rome the blue eyes appear in 22.2%of the population and in medieval Rome in 21.4%, during the empire that figure fell 4.2%. What happened here?
The best known explanation. For Pifferthis agrees with the increase in European northwestern descent during those periods. During the first period, although the genetic base is mostly anatolia, there was a high influence of Yamnas groups. During the last one, the arrival of Germanic groups “such as longobardos and ostrogods” would change the general genetic mix.
On the other hand, during the years of Roman hegemony, the most purely Latin features had disproportionate prestige that caused a boom of brown eyes. For years, this has been part of the consensus of populations genetics.
However, it is not so clear. The demograph Lyman Stone He analyzed exhaustively The Roman genomes of those 4,133 samples to determine if we really had sufficient data to talk about the eyes of the Romans. Their conclusions, between failures in dating and historical confusion, are that we do not have them.
According to Stone, there are reasons to think that in the metropolitan area of Rome the blue eyes were reduced (as a consequence of the increase in immigration). In the same way, it is very likely that in the empire there were more people with brown eyes in 200 d. C. that in 300 d. C. (After all, the Empire grew hugely). This is true even if Bologna’s genetics did not change at all.
What about blue eyes, then? It is a question that, for the first time, we have technology to answer. However, we have no samples to do so. As Lyman saidold DNA is a fantastic tool, but it is still difficult to interpret correctly.
So the answer to the initial question (why (do we believe) the Romans did not have blue eyes?) It is simple: because we do not have enough data. And this configures our world vision much more often than we are willing to admit.
Image | Amanda Dalbjörn | Clemens van Lay
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