According to a recent study published in the scientific academic journal General Certificate of Secondary Education (GCSE), blue-eyed people, who are known to make up 8 to 10 percent of the world’s population, descend from a common ancestor.
For many years, researchers have been trying to determine what causes this change by studying the OCA2 gene, which determines the level of brown pigment in the human eye.
However, it turns out that the genetic mutation that leads to blue eyes is caused by a completely different gene called HERC2, which turns off OCA2 completely and dilutes the brown to blue.
According to scientists from the University of Copenhagen, blue eyes are the product of recessive genes and the source is a common ancestor who lived in southern Europe, around the Black Sea, between 6 and 10 thousand years ago.
Although there is still much research to be done, the mutation is thought to have spread when people migrated from Africa to Europe, which may help explain why there are more blue-eyed people among people of European descent.
The study also looked at variations in other less common eye colors, such as green, which reinforces the idea that the blue eye gene originated in a single individual.
The study’s author, Professor Hans Eiberg from the Department of Cellular and Molecular Medicine, told Science Daily:
“Green eyes can be explained by the reduced amount of melanin in the iris. Blue-eyed people also share a common ancestor, which is a lot more than what we learned in science class.”
How do people get blue eyes?
The iris is the colored part of your eye that has more than one layer. The top layer, called the epithelium, is where melanin, the pigment that gives the eye its color, is found.
Blue eyes have no melanin in the iris. The blue color comes not from the pigment, but from the light reflected in the water in the eye and the layers below it. So, at least biologically, blue eyes are actually colorless.
For a child to have blue eyes, both parents must pass on the blue eye gene. This does not mean that the parents themselves have to be blue-eyed.
They may carry the gene, but it is recessive. However, if both parents have blue eyes, it is almost certain that the child will also have blue eyes.
A person with a genetic mutation has children and this trait is passed on to the next generation. The blue eye mutation continues to spread in many parts of the world, as this generation also has children and they spread everywhere, bg-voice reported.