Blue eyes, their owners share the same (only) ancestor on Earth

Every blue-eyed person on Earth can trace their ancestry back to a single individual who lived between 6,000 and 10,000 years ago. Scientists found that, a long time ago, all humans had brown eyes until a specific genetic mutation made them change.

Blue eyes, the mutation

The mutation stems from a gene called HERC2. Scientists say this gene turns off OCA2, another gene that regulates the amount of brown pigment that develops in the eye. The first person to have blue eyes is believed to have lived in Europe up to 10,000 years ago. And every blue-eyed person alive today has the same mutation present in their body. But it is a very specific type of genetic mutation, which meant that while the eyes turned blue, the hair and skin color still retained the same pigment levels. A complete shutdown would result in albinism.

The nuances

While there is quite a large variation in the shades of the iris between green and brown, blue eyes have little variation in the amount of melanin present. And it is this fact that led Professor Eiberg of the University of Copenhagen to suggest that blue-eyed individuals are all related to the same ancestor. “They inherited the same switch in exactly the same place in their DNA,” he said. Basically, eye color is the result of a genetic wheel of fortune. Although brown is generally considered to be the most dominant gene, two brown-eyed parents won’t necessarily create a brown-eyed baby. It is actually quite possible for two brown-eyed parents to have a blue-eyed child and vice versa.

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About Banner Leon

Videogames entered his life in the late '80s, at the time of the first meeting with Super Mario Bros, and even today they make it a permanent part, after almost 30 years. Pros and defects: he manages to finish Super Mario Bros in less than 5 minutes but he has never finished Final Fight with a credit ... he's still trying.

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