Blue Eyes Trace Back to a Single Ancestor, Study Reveals
In a groundbreaking study, researchers have traced the origin of blue eyes to a single ancestor.
Sam Morgan
- 2023-12-29
- Updated 02:57 PM ET
(NewsNibs) - A team at the University of Copenhagen has published findings that suggest every individual with blue eyes shares a common ancestor. The ten-year-long research, examining eye color of people in multiple countries, including Denmark and Turkey, concluded that a genetic mutation between 6,000 to 10,000 years ago is the source of blue eyes. Originally, all humans had brown eyes, but a mutation affecting the OCA2 gene on the human chromosomes introduced a switch that halted the production of brown eyes.
Genetic Mutation's Role in Eye Color
The OCA2 gene is responsible for instructing the production of the P protein, linked to the melanin content in our bodies. Melanin is the pigment determining the color of our eyes, skin, and hair. It's the variable melanin concentration in the iris, controlled by this gene, that dictates if eyes are brown, blue, or green. The specific mutation associated with blue eyes doesn't deactivate the OCA2 gene entirely but narrows its function, reducing melanin in the iris, hence creating blue eyes instead of brown. Absence or complete destruction of this gene's function would lead to albinism, marked by a lack of melanin throughout the body.
Implications for Blue-Eyed Individuals
Albeit this genetic variation leading to blue eyes has no significant positive or negative effect on human survival, it does bring about certain characteristics. People with this eye color tend to experience better night vision due to reduced melanin, although they have higher light sensitivity, and a more pronounced red-eye effect in photographs. The key aspect of this study is the identification of the exact switch in DNA, confirming the shared lineage among all individuals with blue eyes to one progenitor.
The conclusion of the study not only offers insight into the genetic mechanics behind eye color but also intriguingly maps a part of human ancestry, pinpointing a single common ancestor from whom blue-eyed individuals today inherit their distinctive ocular trait.
