Blue is the second most common eye color globally, with an estimated 8 to 10% of people having blue eyes. A majority of these people are of European descent; however, Black people can be born with blue eyes, even though it’s pretty rare. To understand how this uncommon occurrence can happen, you must first look at the origins of blue eyes, which scientists say is a fairly newer phenomenon.
“Originally, we all had brown eyes,” Professor Hans Eiberg from the university’s Department of Cellular and Molecular Medicine argues in the study.
Distribution of eye color worldwide.
The Role of the OCA2 Gene
The OCA2 gene, formerly called the P gene, is a gene code that produces a pigment called melanin, according to scientists with Medline Plus. Scientists believe the mutation altered the amount of melanin produced in the iris of the eyes.
Europe has the widest variety of eye color, according to Custers, who adds those of European descent are the largest population of blue eyes. Europe was the epicenter of the blue-eye gene mutation. Custers’ research suggests that Black people with blue eyes are affected by the same OCA2 genetic mutation in the same way any other human is, despite the mutation originating in Europe.
Read also: The Allure of Blue and White Tile
In 2008, scientists made a huge breakthrough in understanding eye color. They found a genetic difference in blue-eyed people, in a gene called OCA2. The OCA2 gene makes a lot of sense as an important part of eye color. It is one of many genes involved in making melanin, the pigment found in skin, hair, and eyes. Brown eyes have a full amount of melanin, while any other eye color has less. Since 2008, scientists have found several exceptions to this rule. However, this change is still the primary known contributor to eye color variation.
Most people with blue eyes have this genetic difference near the OCA2 gene. To figure this out, the scientists in the 2008 study took a close look at the genetic sequences of the people with blue eyes. They found that all of the people had exactly the same genetic difference, in exactly the same place. Human DNA is extremely long, with over 3 billion unique positions. The odds that the exact same change happened at the exact same position in a bunch of different people are extremely small.
If the mutation came from a common ancestor, then we would expect the ancestor to not only pass down the mutation itself but also the DNA surrounding the mutation. So if the common ancestor theory is true, then we would expect most blue-eyed people to have the same surrounding DNA at that location. If the mutation arose independently, then we would expect the opposite.
The original mutation in OCA2 arose between 6 and 10 thousand years ago in the Black Sea region of Europe. Shortly after this time, a large-scale migration occurred from the Black Sea to Northern Europe. Less pigmentation was a useful trait in the low-sunlight environment of Northern Europe. People with lighter skin can more efficiently absorb sunlight, which is important for making Vitamin D. While lighter-skinned people also sunburn more easily, it was a beneficial trade-off in that region. After a few thousand years of natural selection, lighter skin, fairer hair, and bluer eyes became prominent in this part of the world.
For example, a research group found several blue-eyed individuals from Norway who did not follow the established pattern. Scientists have also found a few other genetic differences - both near OCA2 and in other genes - that have an effect on intermediate colors. After all, not everyone’s eyes are fully blue or fully brown!
Read also: Comprehensive Guide to African Blue Basil
Ultimately, we know that the most common cause of blue eyes is a single genetic difference in OCA2. It’s very likely that all individuals with this difference share a single common ancestor. We can even trace back the mutation to when and where it took place! However, we also know that some blue-eyed people do not follow this pattern.
More usefully, if you’re asking whether all blue-eyed people share a single common blue-eyed ancestor, that’s not quite true - but the majority of them do!
Genetics of eye color.
I hope this story has demonstrated the immense power of population genetics in uncovering insights regarding our own species.
Human Eye Color Lecture | PART-3 | OCA2 gene | P-protein | melanosomes | Basic Science Series
The Ari Tribe of Ethiopia
The Lower Omo Valley in Ethiopia is one of the most unique regions not only in Africa but in the world. This lush, picture-perfect region is home to so many different peoples, so if you’re looking to run in with a famous Ethiopia Tribe, this is the place to be.
Read also: Morocco's Blue Pearl
Today we’ll take a closer look at the Ari tribe of Ethiopia. These fascinating people are known for their prowess in agriculture and pottery-making. The remoteness of the Lower Omo Valley also means that for the most part, they have been able to retain their cultural integrity, although continued interest shown by the modern world will no doubt erode this eventually.
Ari Tribe of Ethiopia.
The Ari people inhabit the area just outside the town of Jinka and are believed to be the oldest and largest Omo Valley Tribe. It is said that they are the original tribe from which other tribes, including the Mursi, Karo, and Hamer, originated. The Ari people of Ethiopia are said to be one of the most culturally and economically dominant groups in the Omo valley.
They currently live in a clan structure but actually used to live independently until the late 19th century when they were conquered and unified as part of the Ethiopian empire. Like most other Omo Valley Tribes, Ari men are allowed to marry as many women as they want as long as they can provide for their families. However, this practice is becoming relegated as the Ari people embrace Christianity and polygamy becomes less common.
The people are friendly and will often invite you into the villages where you can witness some of their traditional lifestyle activities. Some Ari villages are quite large and contain several streets. Their buildings range from the typical bamboo and straw huts to more substantial structures made from mud and wattle. Many of these buildings feature decorative paintings of animals, people, and cultural symbols in natural colors made from ground charcoal, cow dung, red soil, and water.
In cities and large towns, the Ari people wear regular modern clothes, but in remote villages, you can find Ari women wearing their traditional skirts made from koisha leaves adorned with large colorful bracelets and beads in line with their simple lifestyles. Ari men and women also wear a lot of jewelry and have many ear piercings for decoration. The young boys and girls use innovative ways to adorn themselves using floral decorations and various designs made from berries, corn, cow horns, and warthog tusks to embellish their appearance.
The economic system of the Ari people of Ethiopia is based on farming, which is bolstered by their rather larger territories. Crops consist of grains, wheat, coffee, mangoes, bananas, and various root vegetables. For the Ari people, the use of clay has pretty much become an art form, so you’ll usually see rich displays of Ari pottery at the local market. They are also skilled in metal works, so it’s common to find a few blacksmiths here and there, as well as several of their products at the markets too.
All in all, the Ari people live a simple life, and yet they thrive in their simplicity. If you’re planning a visit to Ethiopia, you should definitely consider paying them a visit.
| Feature | Description |
|---|---|
| Location | Lower Omo Valley, Ethiopia, near Jinka |
| Culture | Known for agriculture and pottery, retain cultural integrity |
| Social Structure | Clan structure, formerly independent |
| Marriage | Polygamy traditional, becoming less common |
| Economy | Farming: grains, coffee, fruits, root vegetables, pottery, metalwork |
| Appearance | Traditional: Koisha leaf skirts, jewelry, piercings, floral decorations |
