A lot of people have the belief that it is very rare for black people to have blue eyes. However, this is not true.
This is because eye color is largely determined by the amount of melanin your body makes. Typically, the more melanin your body produces, the darker your eyes are.
1. They have a common ancestor
Black people with blue eyes all have a common ancestor, and it lived 6,000 to 10,000 years ago in Europe. That ancestor is responsible for the phenotype that we all see today, from Angelina Jolie to Wayne Rooney.
According to researchers at the University of Copenhagen, this ancestor had a genetic mutation that changed their eyes from brown to blue. The gene involved is called OCA2, and it turns off the mechanism that produces the brown melanin pigment in your irises.
The mutated OCA2 gene is linked to other genes that play a role in eye color. These include HERC2, which controls the OCA2 gene’s activity. The HERC2 gene is also connected to another gene that makes P proteins. These proteins are the building blocks for eye pigment.
All these genes interact with each other, so it is hard to tell what color your eyes will be. That’s why a baby can have blue or brown eyes if both parents carry the blue eye gene and one parent doesn’t.
Now, a team led by Professor Hans Eiberg of the Department of Molecular Biology at the University of Copenhagen has found that almost all individuals with blue eyes have the same tiny mutation in their OCA2 gene. This suggests that all blue eyes are derived from a single ancestor who carried the mutation at some point around 6,000 to 10,000 years ago in northern Europe.
The team compared the genetics of blue-eyed individuals from countries as diverse as Turkey and Denmark, and found that the mutation is present in all of them. In fact, the team found that 99.5 per cent of all people with blue eyes have this same gene. Consequently, they suggest that the mutation occurred 6,000 to 10,000 years ago, and spread across the world as people colonised new regions.
2. They have a genetic mutation
In genetics, mutation is the sudden variation of a gene or chromosome that can cause disease. It can also produce “neutral” variations that aren’t caused by disease but by a change in the way a protein works or an alteration in its coding.
These changes can occur in genes that are responsible for blood type and eye color, but they can also occur in a variety of other areas. For example, a change in the genes that make up a person’s hair color can be neutral or even beneficial.
A genetic mutation can occur in a somatic cell (one that’s part of the body) or an embryonic cell that develops from an egg or sperm. Somatic cells are usually only affected by a mutation in that particular cell, but an embryonic cell can affect the entire organism.
Researchers have discovered that people who have blue eyes are almost always a product of a genetic mutation. This mutation occurred 6,000 to 10,000 years ago, according to scientists from the University of Copenhagen.
The mutation that causes blue eyes occurs in the OCA2 gene and the HERC2 gene, which are both involved in the production of pigment in the iris. When these genes don’t work properly, it can cause a reduction in the amount of melanin, or dark pigment, that is produced in the iris.
This reduced melanin can lead to a person having brown or blue eyes. The brown version of the eye color gene is dominant, while the blue version is recessive.
The blue-eyed mutation can be found in a wide range of populations throughout the world. However, it is most common among Europeans.
3. They have a genetic condition
Eye color is influenced by a number of genes that control the amount of melanin (pigment) inside specialized cells in your iris. This results in a variety of shades between blue and brown. Green eyes, on the other hand, are the rarest because they don’t have any melanin. Instead, they look blue because light scatters around the lack of pigment in your iris.
Until recently, scientists believed that your eye color was controlled by a single gene, with the allele for brown eyes being dominant over the one for blue. However, scientists now know that there are at least eight different genes that determine eye color.
The most common is a gene called OCA2, located on chromosome 15. It produces a protein that plays a role in the formation and processing of melanin. The mutations that cause a disease-causing OCA2 variant prevent the production of this protein, so people with this condition are born with albinism.
This gene is present in a wide range of people from all over the world, including many people from Europe. It is also present in a small percentage of people from Africa.
According to the University of California, Berkeley, OCA2 plays a significant role in determining eye color. Researchers have identified several OCA2 alleles that affect how much melanin is produced in the iris. Some of these alleles are associated with brown or blue eyes, while others reduce the concentration of P-protein in a person’s iris.
These genetic conditions can be caused by hereditary factors (passed down through genes) or by random changes that occur before birth. Hereditary factors increase the risk of having a health condition, while random changes happen when you are still developing. This can lead to a range of health problems, from physical ones like allergies and asthma to mental illnesses and behavioral disorders.
4. They have a genetic disorder
Blue is the second most common eye color, with an estimated 8 to 10 % of the population having them. The vast majority of blue-eyed people are of European descent, however, it’s possible for black people to have them too.
According to University of Copenhagen researchers, all blue-eyed individuals share a genetic mutation that took place an estimated 10,000 years ago. This mutation reduced the amount of melanin produced by the iris. This caused light to scatter, creating a blue hue instead of the typical brown color.
This study is a huge discovery. Professor Hans Eiberg of the Department of Cellular and Molecular Medicine at the University of Copenhagen tells Travel Noire that the OCA2 gene is the cause of this mutation.
The OCA2 gene codes for a protein that produces a pigment called melanin. This pigment is responsible for the color of skin, hair, and eyes.
Scientists believe that the OCA2 gene “switched off” about six to 10,000 years ago, reducing the amount of melanin produced in the iris. This triggered the appearance of blue-eyed humans worldwide.
Heterochromia is when someone has more than one eye color, and it can be caused by a variety of health conditions. It usually doesn’t cause any problems, but it is a good idea to consult your doctor if you think you might have heterochromia.
Most of the time, a genetic disorder is diagnosed through a specific test, such as a DNA or chromosome analysis. Other times, your doctor may order blood or biochemical tests to see if an abnormality is present. Depending on the specific disorder, treatment may include diet and nutritional supplements, medication, and physical and occupational therapy to help you stay healthy.
5. They have a genetic condition
If Black people have blue eyes, it is more likely because of a genetic condition than because of colorism. The reason that some black people have blue eyes is because of a genetic condition called ocular albinism.
Ocular albinism occurs when an individual’s body lacks melanin, a substance that gives skin, hair and eyes their color. Often, individuals who have ocular albinism have light-colored hair and eyes, but they can also have brown or clear irises.
Researchers are not sure why some individuals with ocular albinism have blue eyes. But they believe that the cause is a mutation in a gene called OCA2 (formerly known as the P gene).
The OCA2 gene produces a protein called P-protein, which helps to control how much melanin forms in skin and hair. Children who have a mutation in the OCA2 gene do not produce P-protein. This results in a reduction of melanin and causes their eyes to appear blue.
Scientists have also found that some individuals with ocular albinism may be more likely to get a type of eye disease called macular degeneration. Macular degeneration can cause vision problems and make it harder for you to see objects clearly.
However, the main reason that people with ocular albinism have blue or green eyes is because they do not have enough melanin in their iris. This means that when light hits their eyes, it can scatter and make their irises appear blue or green.
This is why some people with ocular albinism have bright blue or green eyes. But this is still a rare condition, so it’s not a big deal. If your baby has a condition that can affect their eyes, talk to your doctor about what you can do.