Study finds that every blue eyed person on Earth is a descendant of one single person

If you have ever pondered over why certain people were blessed with blue eyes, this study might finally put your mind at ease.

Scientists reckon that they have cracked the case - and apparently, it's all down to one single person.

It turns out that before this European individual came along, humans only 'had brown eyes', according to experts at the University of Copenhagen.

But this pioneer completely changed the game around 6,000 to 10,000 years ago, due to a genetic mutation.

As you may remember from your GCSE science days, blue eyes are the result of a recessive gene - meaning you need need two of these for the colour to become apparent.

However, a lot of people were unaware of where these genes even come from, until the boffins in Denmark dug a bit deeper.

The 2008 study revealed some interesting information about the origin of blue eyes (Getty Stock Image)

Professor Hans Eiberg, from the Department of Cellular and Molecular Medicine, led the study which took place back in 2008.

"Originally, we all had brown eyes," he told Science Daily at the time. "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."

Researchers had long tried to discover what caused 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, which spawns blue eyes is from an entirely different gene called HERC2, turns off the OCA2 reducing the production of melanin in the iris and 'diluting' the brown into blue.

But how on earth did the research team determine that this all links back to a common ancestor?

Well, that's because every single blue-eyed person who walks the earth each has this same mutation.

Everyone with blue eyes has the same genetic mutation and therefore, the same common ancestor (Getty Stock Image)

Although there’s still a 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 to explaining why mainly people of European descent have blue eyes.

The 2008 study also looked at the variation in other less common eye colours, such as green, which further proved the idea of one person originating the blue-eyed gene.

Professor Eiberg added: "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."