There are many varying characteristics that make a person unique, from their hair colour, to their height and their skin colour to their shoe size.
And, yet, there’s one characteristic that gives people who share it a lot more in common than you might think.
Everyone who has blue eyes originally shared a common ancestor between 6,000 and 10,000 years ago.
Of course, we know that blue eyes are much rarer than brown eyes, and now it all makes sense, after scientists revealed that the genetic mutation came from a singular human being all those years ago.
Researchers have tried desperately to get to the bottom of the eye colour, studying the OCA2 gene, which determines the level of brown pigment in the human eye, for many years. But they never found the answers they were looking for.
It turns out that the genetic mutation that results in blue eyes is from an entirely different gene, called HERC2, which completely turns off the OCA2, revealing the blue they were born with.
And, how do they know that it all links back to a common ancestor? Because every single blue-eyed person has the exact same mutation.
Although there’s still an awful lot more research that needs to be done, it’s thought that the mutation could have spread when humans migrated from Africa to Europe, which would go some way as to explaining why only people from European descent have blue eyes.
The discovery was actually made back in 2008, when a research team from the University of Copenhagen initially tracked down the mutation.
Professor Hans Eiberg, author of the study, from the Department of Cellular and Molecular Medicine, said as per Science Daily:
Originally, we all had brown eyes. But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a ‘switch,’ which literally ‘turned off’ the ability to produce brown eyes.
Meanwhile, people who have green eyes can be explained by the fact they have a reduced amount of melanin in the iris, which is very different to those with blue eyes.
‘From this we can conclude that all blue-eyed individuals are linked to the same ancestor. They have all inherited the same switch at exactly the same spot in their DNA,’ Professor Eiberg concluded.
Fortunately, the mutation is regarded as neither a negative or positive mutation – unless you have strong feelings about the eye colour, of course!
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