There’s no denying that blue eyes are stunning. However, it’s not common for black people to have blue eyes.
It turns out that there’s a specific gene mutation linked to eye color. At one point, all humans had brown eyes until the OCA2 gene mutated and essentially “turned off” melanin production in the iris.
Origins of Blue Eyes
The origin of blue eyes in black people has long been a subject of speculation. Some scientists believe that it could be due to interbreeding with Neanderthals before their extinction 25,000 years ago. Other theories suggest that it could be due to a genetic mutation. The gene responsible for eye color, called the OCA2, is located on chromosome 15. Those who have blue eyes usually have one copy of this gene and two copies of the gene that makes brown eyes.
According to a recent study by University of Copenhagen professor Hans Eiberg, the recessive OCA2 gene caused all blue-eyed people in the world today to share a common ancestor. The researchers studied the DNA of 800 men and women with blue eyes and found that all had the same mutation at the same spot in their chromosomes.
This particular mutation reduces the amount of melanin in the iris, which causes the light to reflect off the back of the eyes rather than through it. The researchers also found that all blue-eyed people have low levels of the OCA2 gene, which is not typical in the population. The team of scientists concluded that the OCA2 gene changed its expression around 10,000 years ago, and the rest of the human population caught this mutation as a result.
It is believed that all blue-eyed people have the same gene mutation at the same point in their chromosomes, which suggests that they share a very distant common ancestor. The variations in eye color seen in the population today – from green to brown – are explained by other genes in the chromosome that affect how melanin is produced.
Interestingly enough, this same gene is still present in the African population. The only difference is that blacks have much lower levels of melanin, which explains why they are less likely to have blue eyes. In addition, a person’s environment can play a role in their eye color. For example, sunlight can cause the iris to produce more melanin, which can cause a person’s eyes to look more brown or green.
Blue Eyes in Blacks
Despite the fact that they are rare, it is possible for black people to have blue eyes. However, in order for a person of color to have blue eyes, they must have Caucasian relatives on both their mother and father’s side. It can also take several generations for a recessive gene to appear in a family.
Throughout history, a person’s eyes have been prized for their beauty. Frank Sinatra’s were legendary, Paul Newman’s melted millions of hearts and Cameron Diaz dazzles in modern Hollywood. However, the mystery of why some people have blue eyes has eluded scientists for many years. Recently, Copenhagen University researchers solved the mystery by tracing all blue-eyed people to a single mutation that arose as early as 6-10,000 years ago.
As it turns out, the mutation stopped a gene from creating melanin—the pigment that gives skin, hair and eye color. As a result, the eyes turned from brown to blue. The genetic mutation may have originated in a population that lived near the northwest coastal regions of the Black Sea.
Since then, the mutation has spread throughout the world, and today there are blue-eyed people living in Africa, Australia and Europe. In fact, a British television documentary recently featured a man with blue eyes from Kenya.
While there are a few blue-eyed black people, most with the trait live in the United States. They are often mixed race and can have a mixture of Caucasian, Asian and African ancestry. In addition, some blue-eyed blacks can have a genetic condition called heterochromia, which causes the eyes to be different colors at different times.
For example, the eyes can look green under certain lighting conditions and blue at other times. This happens because the iris has low concentrations of melanin, which allows more light to pass through and reflect off of it.
Some of the most famous blue-eyed black people include actress Cydnee Black, former Miss America Vanessa Williams and singer Beyonce. However, there are others with the unique feature that are not as well known. For this reason, many people are confused when they see photos of blacks on social media or in the news with blue eyes. The confusion is based on the misconception that blue eyes only occur naturally in whites.
Blue Eyes in Black Children
Scientists used to think that eye color was determined by a single gene, but they have since learned that multiple genes interact with each other. One of these genes is called OCA2. If a person has a broken OCA2 gene, their skin cells won’t make as much melanin as they should. This causes a person to have blue eyes. A second gene that determines eye color is called HERC2. If the HERC2 gene doesn’t work, a person will have brown eyes. The OCA2 and HERC2 genes work together in a dependent relationship. That’s why it is possible for two people with blue eyes to have a child with brown eyes.
It’s also possible for a person who has no blue-eyed relatives to have blue eyes. This is known as heterozygous blue-eyes, and it happens frequently in Africans.
Black people with blue eyes are extremely rare, but it is possible for them to be born this way. If a black mother and father both carry the blue-eyes gene, their child will have blue eyes. However, if only one parent carries the gene, their child will have brown eyes. It’s also possible for a black person to have blue eyes due to a mutation in another gene, such as the G allele for green eyes.
The first time Jane Elliott became world-famous was when she conducted her infamous “Blue-Eyes, Brown-Eyes Experiment.” It’s now a classic social experiment that’s taught in classrooms around the world. This episode of Skeptically Speaking explores the true story of this fascinating woman and how her experiment reveals much more about tribalism, racism, obedience to authority, role playing and social proof than just eye color.
As it turns out, nearly all blue-eyed people have a common ancestor who lived 6-10,000 years ago. That’s when the OCA2 gene underwent a mutation that made it less likely to produce melanin. A study led by Professor Hans Eiberg analyzed mitochondrial DNA from 155 blue-eyed people from countries as diverse as Denmark, Jordan and Turkey. He found that 97% of them shared the same H-1 haplotype for OCA2. That mutation at the specific location in the genome explains why so many people have blue eyes today.
Blue Eyes in Black Adults
People’s eye colors are based on how much melanin (a natural pigment) their bodies make and store in front layers of the iris. Melanin is produced by cells called melanocytes. Individuals with less melanin have lighter eyes; those with more melanin have darker eyes. Scientists used to think that a single gene determined eye color. Therefore, they believed that two blue-eyed parents couldn’t have a brown-eyed child because they each carried a different copy of the eye color gene.
But in the past decade, scientists have learned that there are many genes that determine eye color. One of them, OCA2, is responsible for blue eyes in blacks and people with other racial heritages. OCA2 is recessive, meaning that someone needs to have two copies of it to have blue eyes.
Most people with blue eyes are of European descent. Those of Asian and African descent, on the other hand, have brown eyes. In fact, about 55% of the world’s population has brown eyes.
While it’s true that most whites have blue eyes, a growing number of blacks are also born with them. It’s thought that this is because of a genetic mutation. The theory goes that about 10,000 years ago, all humans had brown eyes until a single baby was born with a harmless mutation to the OCA2 gene. This caused the gene to “switch off” and reduced melanin production in the iris.
The OCA2 gene is found all over the world, but the majority of blue-eyed people live in Europe. Those of Scandinavian descent have the highest percentage. However, it’s also present in some countries in Africa, Asia, and the Middle East. Hazel eyes (a mixture of green, yellow, and gold) and amber eyes (a mixture of copper, gold, and a light shade of brown) also occur in smaller numbers.
One of the main problems that occurs with having blue eyes as a person of color is discrimination and prejudice. A famous example is the story of Jane Elliott, a pioneer in racism awareness training. She is well known for her “Blue-Eyed/Brown Eyed” exercise, which forces participants to go through an experience similar to the type of discrimination that people of color face in daily life. While the participants of the workshop know that this is a training exercise, the humiliation they feel is real.