Is the original ancestor of all blue-eyed people one?
A team of researchers at the University of Copenhagen has discovered a genetic mutation that occurred 6-10 thousand years ago. The head of that group, Professor Hans Rudolf Licht Eiberg, explained that a person was born with a genetic mutation at one point in time. That mutation limits the amount of melanin in a person’s eyes, which can cause the eyes to turn blue instead of brown. And later, that mutation has gradually spread to the next generation of humanity.
This mutation led to the emergence of blue eyes and is the cause of the color of the eyes of all blue-eyed people in the world today. For many years, researchers have been searching for a gene called OCA2 [the OCA2 gene determines the amount of brown pigment in our eyes]. But in the eyes of blue-eyed people, this gene was not there at all. Mutations have been found in a completely different gene called HERC2. HERC2 inhibits OCA2, which means it expresses blue by inhibiting brown color. Every blue-eyed person has this same mutation.
Blue eyes result from a single genetic mutation: This means that every person with blue eyes in the world has a common ancestor. A team of experts from the University of Copenhagen found that mutation in a single Danish family.
Dr. Iberg’s team published a report in the Journal of Human Genetics that they meticulously mapped blue eye color through genetic linkage analysis. Through that analysis, he discovered that he inherited an identifiable group of genes from single parents.
Science calls a group of genes inherited from a single parent a ‘haplotype.’ The haplotype is found in only 155 blue-eyed people in Denmark and five blue-eyed people in Turkey, and two blue-eyed people in Jordan. In addition to haplotype mapping, said. Iberg’s team conducted mitochondrial DNA analysis, which looked at the types of genetic mutations to trace maternal lineage hundreds of thousands of years ago.
What is a genetic mutation?
You can say that all eyes are the same color. It is because the pigment called melanin, which gives our eyes color, is naturally brown.
“Originally, we all had brown eyes, but a genetic mutation affecting the OCA2 gene on our chromosomes causes a mutation that stops the ability to make brown eyes,” said Hans Rudolf Licht Iberg, a professor of cellular and molecular biology at the University of Copenhagen. “The OCA2 gene codes for the so-called P protein, which is involved in the production of melanin. This pigment colors our hair, eyes, and skin.
Changes in the OCA2-linked gene do not entirely disable or shut down the gene. Instead, it restricts its activity to reduce the production of melanin in the iris of the eye. It effectively makes brown eyes blue. The effects of changes in OCA2 are particular. If the OCA2 gene were utterly destroyed or shut down, melanin deficiency would occur in human hair, eyes, or skin color. It is a condition known as albinism.
The way this mutation started
Probably, when people started coming to Europe from Africa. It explains why blue eyes are only seen in people of European descent. You can also say that all blue-eyed people are descendants of a single European ancestor. It reveals an impressive family tree!