Scientists have tracked down a genetic mutation which took place 6,000-10,000 years ago and is the cause of the eye color of all blue-eyed humans alive on the planet today. At one time, it was believed that eye colour including blue eyes was a simple genetic trait, and therefore you could predict a child's eye colour if you knew the colour of the parents' eyes and perhaps the colour of the grandparents' eyes. The biological purpose of mating is to shuffle DNA, so doing so is against the grain. While this inheritance conferred an immunity advantage to modern Eurasians, it also made them more prone to some autoimmune reactions. It goes against the biological aim of mating, which is the shuffling of DNA. Krystina is a Technical Writer with a background in healthcare. What do the numbers on your eyeglass frames mean? Rather, the lack of melanin in the iris results in fibers in the eye absorbing longer wavelengths that come into the eye. Because of this, many babies have blue eyes, but their eye colour changes as the eye develops during early childhood and more melanin is produced in the iris. Financial support for ScienceDaily comes from advertisements and referral programs, where indicated. Between 2% and 6% of modern northwestern Europeans have red hair, compared with an average of around 0.6% of the worlds population as a whole. Also, the anatomic structure of the iris can affect eye colour to some degree. Similar to darker skins ability to endure the hot sun for longer, this probably had evolutionary advantages. Lighter eyes appear to change colors like a chameleon when the lighting changes. It ran in the family of the ancient Egyptian pharaohs of the 18th dynasty, to which Tutankhamun (1341 BC 1323 BC) belonged. This is significant because recessive alleles are responsible for some congenital defects and genetic diseases, like cystic fibrosis. This form of hearing loss comes from damage to the inner ear or to the nerve going from the ear to the brain. It is treated with a healthy diet and increased physical activity, plus medication and/or insulin as required. Similar to how it does with blue and green eyes, the light scatters. He enjoys playing sports and watching movies together. Whats the Difference Between Vitiligo and Albinism? As Professor Eiberg says, "it simply shows that nature is constantly shuffling the human genome, creating a genetic cocktail of human chromosomes and trying out different changes as it does so.". He didnt speak until he was four, couldnt walk until he was eight and was barely able to chew due to his deformed jaw. This is important as certain congenital defects and genetic diseases, such as cystic fibrosis, are carried by recessive alleles. "From this we can conclude that all blue-eyed individuals are linked to the same ancestor," said Eiberg. One of the mutations in the main gene for modern human hair color appears to be of ingrade origin and may have helped European hair color to diversify by providing raw material for selection to act on. This can make the blue eyes look slightly different depending on the type of lighting conditions. (Check for Can Black People Have Blue Eyes? Red Eye Inbreeding; perhaps best left to the mites. Inbreeding - Definition and Examples - Biology Online Dictionary It could be an influence on the modern human aquiline nose prevalent in the ingrade hotspots of southern Europe and the Near East, and amongst native North Americans whose genetic source has been traced to the Altai mountains of East/Central Asia. We were all taught that parents with blue eyes have kids with blue eyes. While limited, there is some research showing that blue eyes may protect you against seasonal affective disorder. If you stayed awake during high school biology, you might find this answer surprising. A 2015 study examined 259 adult Egyptian mummies and found that royal mummies had consistently different heights from the general population, with male royals being taller than average and female royals being shorter than average. Blue eyes as a risk factor for type 1 diabetes. Dog How to choose the best glasses for your face shape, Optometrist vs ophthalmologist vs optician, researchers at the University of Copenhagen, Computer vision syndrome & digital eye strain: Symptoms & treatment, A study of European Americans with blue eyes, FIND AN OPTICIAN OR OPTICAL SHOP NEAR YOU, How to clean glasses and remove scratches, How to get rid of the red eye effect in photos, How to put in eye drops: A step-by-step guide. When people think of albinism, they may picture people with white hair, pale skin and pink eyes. Brown eyes have the highest amount of melanin in the iris, and blue eyes have the least. Dominant and recessive genes refer to inheritance patterns and indicate the likelihood that a particular trait will be passed down from one parent to the next. 20,000 pedigree boxer dogs would have the generic variety of around 70 dogs. To date, scientists have found >150 genes responsible for the manifestation of a person's eye color. It isnt yet known if Neanderthals suffered from these diseases themselves, or if these mutations affected only modern humans when they were implanted into our genetic code: Type 2 diabetes develops when the body is unable to produce enough workable insulin the hormone that helps release the glucose in your blood to give you energy. Human DNA is bundled into 23 pairs of chromosomes, within each chromosome there are hundreds of thousands of genes and what's more, each gene has two copies known as alleles. The color of our eyes depends on how much melanin is present in the iris. You can find out more about our use, change your default settings, and withdraw your consent at any time with effect for the future by visiting Cookies Settings, which can also be found in the footer of the site. Blue eyes in humans were caused by a recessive trait mutation, which prevents melanin production in the iris inside the eyes and is not reliable for inbreeding. "But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a 'switch', which literally turned off the ability to produce brown eyes.". The iris has two layers. In theory, blue eyes may have protected a person from acquiring vision disorders caused by these periods. Having evolved in Eurasia over hundreds of thousands of years, Neanderthals developed the HLA receptor that provided them with immunity against the many local pathogens that lurked in the forests, rivers and caves of Europe and Asia. But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a switch, which literally turned off the ability to produce brown eyes.. Scientists have tracked down a genetic mutation which took place 6,000-10,000 years ago and is the . Researchers at the University of Copenhagen have located a genetic mutation that occurred between 6,000 and 10,000 years ago and is responsible for all living people with blue eyes. Mujica-Mota MA, Schermbrucker J, Daniel SJ. carrots Outside of a few exceptions, nearly everyone has eyes that are brown, blue, green or somewhere in between. Also, adding an anti-reflective coating to photochromic lenses gives you the best vision and comfort in all lighting conditions (including driving at night) while showcasing your blue eyes with reflection-free lenses. He is a passionate advocate for education, and he believes that every student should have access to a quality education. flight The amount and distribution of brown melanin on the two layers of the iris are what cause the variations in eye colors. What Are The Causes? One theory is that blue eyes were immediately considered an attractive feature, causing people to seek mates with blue eyes to have children with, enabling the genetic mutation to multiply.