All Blue-Eyed People Have Same Ancestor

February 9, 2009

Blue Eyes, a Genetic Mutation from a Common Ancestor

I’m happy to report that this blue-eyed woman is related to Brad Pitt and Paul Newman. A Danish professor has traced the evolution of blue eyes to a genetic mutation dating back 6,000 to 10,000 years — somewhere in the near or Middle East — and has concluded that all blue-eyed people have a shared ancestor and thus all are related. Professor Hans Eiberg, of the Department of Cellular and Molecular Medicine at the University of Copenhagen, said in a press release that, originally, all people had brown eyes but that a gene now called OCA2 “literally ‘turned off’ the ability to produce brown eyes.”

Eiberg, who has researched OCA2 since 1996, says that OCA2 affects melanin production: melanin being the pigment which colors our eyes, hair and skin. OCA2 reduces melanin levels in eyes, thus creating blue eyes (As a further example, a person without any melanin is an albino.). Eiberg explained that all blue-eyed people “have all inherited the same switch at exactly the same spot in their DNA. From this, we can conclude that all blue-eyed individuals are linked to the same ancestor.”

Map of the Black Sea

Professor Eiberg’s “best guess” as to where the mutation took place is the near eastern or northwestern area of the Black Sea region. This is where a large agricultural migration to northern Europe occurred during the Neolithic period (6,000 to 10,000 years ago). However, Eiberg added that the Black Sea region is only his “best guess.” He mentioned that the origin could also be in “the northern part of Aghanistan.” Eiberg’s discovery was reported in an online edition of the Human Genetics journal.

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