If you have blue eyes, you probably know how rare your peepers are. It’s estimated that only eight percent of the population has blue eyes! While we happen to think all eyes are beautiful eyes, it turns out that blue-eyed folks have more in common than just their eye color — they’re actually all distantly related. Let us explain.
According to a 2008 study conducted by a team of researchers at the University of Denmark, the blue eyes trait can be traced back to a single ancestor. About 6,000 to 10,000 years ago, the genetic mutation for blue eyes first appeared. Before then, all people had brown eyes, professor and researcher Hans Eiberg wrote.
A mutation in the OCA2 gene, Eiberg says, allowed the body to essentially turn off or reduce the gene’s ability to produce melanin — the pigment that gives our hair, skin, and eyes their color. While the mutation did not allow the gene to completely “switch” off our melanin production (if that occurred, albinism would be the result), it did reduce the amount of melanin produced. The result is that melanin could be “diluted” to produce blue eyes instead of brown.
So what was it in his research that led Eiberg and his team to conclude that all people with blue eyes are related? Melanin levels can vary a lot from person to person; that’s why there are so many different eye colors. However, while there is a large range of melanin levels in people with brown eyes, people with blue eyes all have relatively the same levels of melanin. “From this we can conclude that all blue-eyed individuals are linked to the same ancestor,” Eiberg said. “They have all inherited the same switch at exactly the same spot in their DNA.”
If all of you brown-eyed girls out there are feeling a bit bummed that you don’t share a bond like blue-eyed people, don’t worry: Having blue eyes is not a positive or negative thing, Eiberg says. It’s simply an indicator that “nature is constantly shuffling the human genome, creating a genetic cocktail of human chromosomes and trying out different changes as it does so.” That said, if you’re really unhappy with your natural eye color, you can always go the colored-contacts route!
h/t Science Daily