September 29, 2016
Is It True That Everyone With Blue Eyes Is Related To One Single Ancestor?

Is it possible that blue-eyed celebrities like Brad Pitt, Katy Perry and Taylor Swift all share the same single ancestor? Is there something deep in our psyche that makes us find blue eyes so irresistible? You may be surprised by this answer! A Danish study claims that at one time, everyone had brown eyes until a genetic mutation created the first blue-eyed person. They also have a theory about the appeal of blue eyes and why there are hundreds of millions of people on earth with that eye color.

Researchers from the Institute of Forensic Genetics at the University of Copenhagen made the discovery that a genetic mutation is the reason behind the first pair of blue eyes. The researchers studied blue-eyed subjects from Denmark, Turkey and Jordan. The study compared the eye color of people from each country as well as the mitochondrial DNA. According to lead author Professor Hans Eiberg, researchers uncovered evidence that demonstrates that one single person is the ancestor of all people with blue eyes.
"All of them, apart from possibly one exception, had exactly the same DNA sequence in the region of the OCA2 gene. This to me indicates very strongly that there must have been a single, common ancestor of all these people."
Professor Eiberg says that everyone had brown eyes and genetic mutation "turned off" our ability to create brown eyes. Blue eyes are not really a color as much as it is a lack of color. More of the mutation and the person is an albino.
"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."
The researchers estimate that this happened sometime between 6,000 and 10,000 years ago, in the Black Sea region of Europe. They believe this anomaly occurred during the great migration from the Middle East to Northern Europe. The theory is that this eye color mutation occurred in the midst of the big expansion, when farming was the main source of food and people scattered all over Europe.
"The mutations responsible for blue eye color most likely originate from the north-west part of the Black Sea region, where the great agricultural migration of the northern part of Europe took place in the Neolithic periods about 6,000 to 10,000 years ago."
What is also fascinating is that culturally, instead of being shunned, the one person with this new eye color was obviously considered attractive. Professor Eiberg clearly states that blue eyes are more attractive to potential suitors than brown eyes, thus confirming that this is indeed an attractive genetic mutation.
"Blue eyes are more attractive to potential partners than brown. One mutation 10,000 years ago has today resulted in almost 200 million pairs of blue eyes, and people with blue eyes have more blue-eyed children"
Science Daily points out that mutations are considered neutral. They are neither good nor bad. Other mutations include hair color, freckles, baldness and other inherited characteristics. The professor says that these mutations are nature's way of trying to experiment with all of the possible genetic combinations.
"It simply shows that nature is constantly shuffling the human genome, creating a genetic cocktail of human chromosomes and trying out different changes as it does so."
While Professor Eiberg reported that there is now nearly 200 million people on the planet with blue eyes, it should be noted that less than 15 percent of all Americans have blue eyes. This was not always the case. Before the 20th century began, over half of all Americans were blue-eyed. There are a few countries with a higher percentage of blue eyed people including 48 percent of all people in the United Kingdom who have the desirable eye color and of course, most Scandinavian countries, over 90 percent of all people have blue eyes.
The six-letter sequence is exactly the same in humans as it is in dogs, cats, monkeys, chimpanzees, mice, cows and rats. The mutation is the reason for the switch. The blue eyes that are often seen in Siberian Huskies is achieved from careful breeding, while blue eyes in Siamese cats is achieved due to a type of albinism. The particular mutation discovered in this study only applies to humans.

So do you think there is something extra alluring about Chris Hemsworth's deep blue eyes that makes us pay closer attention to what he has to say? Do you think it is cool that everyone who has blue eyes is actually related?

[Featured Image by Frazer Harrison/Getty Images]