If you have blue eyes, you are part of a large global family that dates back to a single person who lived between 6,000 and 10,000 years ago. This is the astonishing result of a major scientific study.
Incredibly, all blue-eyed people share a common ancestor. This astonishing revelation is the result of research by a team of scientists from the University of Copenhagen, who shed light on a genetic mutation that occurred around 6,000 to 10,000 years ago, as Professor Eiberg tells in Science Daily .
Researchers have long been interested in eye color, trying to understand why some people have brown, green, or blue eyes. In fact, this color depends on the quantity and quality of melanin present in the iris. For example, people with green eyes have a reduced amount of melanin compared to those with brown eyes, but it’s a different story for blue eyes.
The researchers looked in detail at the OCA2 gene, known to determine the level of brown pigment in the human eye. However, it is not the OCA2 gene that is directly responsible for blue eyes. In reality, the genetic mutation comes from another gene, called HERC2. This gene acts as a kind of switch. When activated, it deactivates the OCA2 gene, preventing the production of melanin, the pigment that gives eyes their brown color. It is this absence of melanin in the iris that gives blue eyes. This mutation is the same for all people with blue eyes, meaning they all inherited the same switch, located in exactly the same place in their DNA.
Professor Hans Eiberg, an expert in this field, explains that this specific mutation is a great example of how changes in our DNA can have visible effects. People with blue eyes therefore share not only a physical characteristic, but also a unique genetic connection.
The origin of this mutation dates back to a time when humans were migrating and mixing, which allowed this mutation to spread. This occurred before human societies stabilized and became settled, meaning that the common ancestor of all blue-eyed people could have lived in a now undetermined geographic region, perhaps somewhere in Europe or Asia.
This ancestral connection is a magnificent illustration of the interconnectedness of humanity. Even though we live in different corners of the world and our cultures and languages are diverse, it’s fascinating to think that a simple characteristic like the color of our eyes can connect us in such a profound and unexpected way.