Blue eye color in humans may be caused by a perfectly associated founder mutation in a regulatory element located within the herc2 gene inhibiting oca2 expression. Heres what made those brown eyes blue health nbc news. 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. Now the tricky part is coming up with that advantage. His new book, who we are and how we got here, charts the myriad ways the study. The research showed that those who have blue eyes have a single common ancestor. Blue eyes are quite rare in some parts of the world and extremely common in others. The human eye color is a quantitative trait displaying multifactorial inheritance. The mutation occurred between 6,000 and 10,000 years ago.
Without melanin to give eyes their brown color, they became blue. It is one of several mutations such as hair color, baldness, freckles and beauty spots, which neither increases nor reduces a humans chance of survival. Our eye color depends on that of our parents or grandparents. A team at the university of copenhagen have tracked down a genetic mutation which took place 610,000 years ago and is the cause of the eye colour of all blueeyed humans alive on the planet today. It is caused due to specific interactions between the oca2 and herc2 gene. Eye color is a polygenic phenotypic character determined by two distinct factors. The afflicted individuals eyesight is said not to be compromised, even as the color of the eyes deepen to a darker shade of.
And blue eyes seem to captivate humans perhaps more than any other variation of eye color. Blue or almost black, slategray, golden or violet or fainted green. And all blue eyed people are genetically related to a person who lived in the black sea region sometime between 6 10,000 years ago. By looking at the dna around the blue eye mutation, scientists can see that blue eyes have been strongly selected for. Blue eyes originated 10,000 years ago in the black sea. By association analyses, we identified two snps within. The laws of genetics state that eye color is inherited as follows. This mutation turned off the mechanism which produces melanin in the iris of the eye. In 2008, he published a study which confirmed that blue eyes were a genetic mutation by a single person who lived. The genome is composed of one to several long molecules of dna, and mutation can occur potentially anywhere on these molecules at any time. According to wikipedia yeah i know not always a reliable source, but good enough for lsa lol, blue eyes are indeed a genetic mutation. Blue eyes has to do with the amount of pigment melanin in the eye produces a little produces blue eyes, a medium produces greenhazel eyes and the most produces brown eyes. They say that blue eyes are a result of a mutation that took place at some point during the last 10,000 years. People with blue eyes have a single, common ancestor, according to new research.
The history of science began with people who believed in god a very. Blueeyed humans have a single, common ancestor sciencedaily. Several studies have shown that the oca2 locus is the major contributor to the human eye color variation. Eye colour is determined by variation in a persons genes. Introduction the eye color variation is a result of variable amounts and. New research shows that all blueeyed people share a common ancestor. In africa dark eyes, skin and hair are the norm, but blue eyes are more common in southern europe and even more common in northern europe, where 70 per cent of people have blue eyes. The mutation of brown eyes to blue represents neither a positive nor a. I believe this to be a subtle troll regarding aryan race and hitler, if it does confer a beneficial advantage blue eyes tied to the. The answer according to scientists could only be attributed to genetic mutation or waardenburg syndrome ws,which is a rare 140,000 disease characterized by sensorineural deafness in association with pigmentary anomalies and defects of neuralcrestderived tissues. For most pigmentation genes, the allele for darker colors is stronger, or dominant. Heterochromia how many different eye colors are there. And all blueeyed people are genetically related to a person who lived in the black sea region sometime between 6 10,000 years ago.
This person lived more than 6,000 years ago and carried a genetic mutation that has now spread across the world. Research has found that almost everyone with blue eyes is linked to an ancient genetic mutation, and a small fraction get their blue eye color as a result of a health condition such as ocular albinism, which affects the. Mutationism is one of several alternatives to evolution by natural selection that have existed both before and after the publication of charles darwins 1859 book, on the origin of species. The secular story maintains that blue eyes are the result of a genetic mutation that occurred in the recent evolutionary history of humans. The surprising origin of blue eyes, a team at university of copenhagen conducted a study in 2008 about the formation of blue eyes. These days there are about 300 million people worldwide that carry the mutation that results in blue eyes. Before that, a majority of all people had brown eyes whereas only a few displayed light colored eyes. The actual number of genes that contribute to eye colour is not yet known, but so far it is detected that fifteen genes have been associated with eye colour inheritance. Heterochromia also known as a heterochromia iridis or heterochromia iridum is not necessarily a mutation but it can be a genetic trait in which ones eyes are both a different color or where a part of one iris is a different. They did not have a lot of the skinlightening mutations that are present in the. Blue eye color in humans may be caused by a perfectly. It is one of several mutations such as hair colour. Although the odds of having blue eyes are markedly lower than having brown eyes, blue isnt the rarest of all eye colors.
The most serious changes take place in the functional units of dna, the genes. The two genes oca2 and herc2 play a major role in eye colour which is located in a particular region of chromosome15. Strictly speaking a mutation is a change in a gene. In the theory, mutation was the source of novelty, creating new forms and new species, potentially instantaneously, in a sudden jump. But it looks like the two events simply happened to occur in the s. Researchers find all blueeyed people come from the same. Haitian girl with beautiful blue eyes so why are some few black people have blue eyes nowadays. They found a genetic mutation that took place between 6000 10,000 years ago which is the reason behind the occurrence of blue eyes and the causation of all blue. Still, blue eyes are very uncommon among black people, especially those with no caucasian ancestry. How blue eyes came to exist through one ancestors genetic. If two parents only carried genes for green eyes and had a chi. Indeed, blue eyes are distinct, powerful, piercing, complicated and undeniably beautiful. This narrative is rooted in the belief that modern humans originally evolved from darkskinned, darkeyed ancestors from africa. Researchers at the university of copenhagen suggest that a mutation that arose around 6,000 to 10,000 years ago was inherited by every individual who has blue eyes original study here.
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. Blueeyed humans have a single, common ancestor university of. This is another piece of evidence that blue eyes came from a single common ancestor. If one of the parents has a different eye color, that color is usually seen in the progeny. All blueeyed people have one ancestor in common, born around 6,000 to 10,000 years ago. Blue eyes in modern humans are related to the same mutation in a. A team of researchers from copenhagen university have located a single mutation that causes the mysterious phenomenon of blue eyes.
This individual had a genetic mutation occur to the gene oca2, which controls eye color. Shuffling of genes nature is responsible for the shuffling of genes. The mutation of brown eyes to blue represents neither a positive nor a negative mutation. Under the beneficial mutation heading, there is blue eyes being listed. Scientists have tracked down a genetic mutation which took place 6,00010,000 years ago and is the cause of the eye color of all blueeyed. Origin of blue eyes understanding genetics the tech interactive. People with blue eyes have one common ancestor who. One common ancestor behind blue eyes according to new research a team of scientists has tracked down a genetic mutation that leads to blue eyes.
So if two parents both only carrying genes for blue eyes had a child with green eyes then a mutation is the most likely expectation. Red hair, blue eyes, and other genetic mutations in humans. If both parents have blue eyes, the children will have blue eyes. By linkage analysis of a large danish family, we finemapped the blue eye color locus to a 166 kbp region within the herc2 gene. New research shows that people with blue eyes have a single, common ancestor. The mutation of brown eyes to blue ones does not represent a positive or negative mutation, its like many other mutations including baldness, hair color, freckles, and beauty spots, none of which affect chances of survival. The family tree of blueeyed individuals the genetic. It is said that the condition is a mutation of the genes, which manifests itself in the fact that the eyes change color, from blue to purple, within the first six months after birth. The secular story maintains that blue eyes are the result of a genetic mutation that occurred in the recent evolutionary history. For example, about 99 percent of the people from the area around the balkans or the black sea have blue eyes. This probably happened a number of times throughout human history. The progeny only has blue eyes if both parents also have a blue eye color. The origin of black people with blue eyes owlcation. Ancient dna is rewriting human and neanderthal history the.
Hence, our data suggest a common founder mutation in an oca2 inhibiting regulatory element as the cause of blue eye color in humans. No the weird part is that the blue eye mutation from that original ancestor. If you were to propose to me a mechanism how having blue eyes would lead to someone inventing agriculture, i would be willing to accept it. How one ancestor helped turn our brown eyes blue the independent.
Blue eyes, red hair and other genetic mutations through our dna. A child can be born with blue eyes but the eye color can change later. When it comes to the history of basic human traits, an evolutionary myth about eye color often pops up. The oca2 gene determines how much brown pigment is in our eyes. Blue eyes, red hair and other genetic mutations through. Ever since that single event, no mutations have arisen in this gene and thus is considered most likely to be the cause of all the blueeyed humans alive presently.
First ol blue eyes is 7,000 years old and was a caveman. You only need to inherit one brown eye allele to see the color. However, in northern europe a mutation arose in a gene known as oca2 that disrupted melanin production in the iris and caused the eye colour. I dont usually edit wikipedia articles, so im hoping a good samaritan will do it for me. The blue eye mutation dates back to 610 thousand years ago when the main gene associated with the eye color, oca2, underwent a mutation in a single human.
The mutation in the adjacent gene does not switch off the oca gene entirely but limits its action, reducing the production of melanin in. Scientists have tracked down a genetic mutation which took place 6,00010,000 years ago and is the cause of the eye. All blueeyed people have a single ancestor in common. A team of scientists has tracked down a genetic mutation that leads to blue eyes. So you have this unusual look of dark skin and blue eyes. The research was published in the journal of human genetics. For years, researchers had searched for it on the oca2 gene. Albinism is just a mutation with the absence of melanin, while people with white skin, lighter hair such as blonde and lighter eye colors such green, blue, grey, bluegreen, etc are just characteristics of low to moderate amounts of melanin and other factors, which are totally different from individuals with albinism. My friend who is hispanic told me that incest occurred at some point in my family because my brother has blue eyes and that blue eyes mean incest. Blue eyes result of ancient genetic mutation telegraph. The progeny only has blue eyes if both parents also have a. So for example, a gene that affects eye color could come in two versions. The brown or black eye color is usually dominant over it.
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