Posted on 01/30/2008 2:10:37 PM PST by decimon
New research shows that people with blue eyes have a single, common ancestor. A team at the University of Copenhagen have tracked down a genetic mutation which took place 6-10,000 years ago and is the cause of the eye colour of all blue-eyed humans alive on the planet today. What is the genetic mutation
“Originally, we all had brown eyes”, said Professor Eiberg from the Department of Cellular and Molecular Medicine. “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 OCA2 gene codes for the so-called P protein, which is involved in the production of melanin, the pigment that gives colour to our hair, eyes and skin. The “switch”, which is located in the gene adjacent to OCA2 does not, however, turn off the gene entirely, but rather limits its action to reducing the production of melanin in the iris – effectively “diluting” brown eyes to blue. The switch’s effect on OCA2 is very specific therefore. If the OCA2 gene had been completely destroyed or turned off, human beings would be without melanin in their hair, eyes or skin colour – a condition known as albinism. Limited genetic variation
Variation in the colour of the eyes from brown to green can all be explained by the amount of melanin in the iris, but blue-eyed individuals only have a small degree of variation in the amount of melanin in their eyes. “From this we can conclude that all blue-eyed individuals are linked to the same ancestor,” says Professor Eiberg. “They have all inherited the same switch at exactly the same spot in their DNA.” Brown-eyed individuals, by contrast, have considerable individual variation in the area of their DNA that controls melanin production.
Professor Eiberg and his team examined mitochondrial DNA and compared the eye colour of blue-eyed individuals in countries as diverse as Jordan, Denmark and Turkey. His findings are the latest in a decade of genetic research, which began in 1996, when Professor Eiberg first implicated the OCA2 gene as being responsible for eye colour. Nature shuffles our genes
The mutation of brown eyes to blue represents neither a positive nor a negative mutation. It is one of several mutations such as hair colour, baldness, freckles and beauty spots, which neither increases nor reduces a human’s chance of survival. 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.”
On the next Maury!
Seriously, the answer is yes, and here's a good explanation: http://www.thetech.org/genetics/ask.php?id=2
I have never seen eye color like that. Wow.
That is a question for your mother.
I wish I could share info like this with my wife, but she’s a 6000 year old earth/Adam and Eve riding dinosaurs creationist and freaks out about such science.
:) :) :) :) :)
thanks, bfl
which ones are Vladimir Putin and which are Daniel Craig?
my mom had blue eyes, my dad had brown eyes, we all 9 of us have blue eyes.
You may want the send this article to your dad.
My father has green/brown hazel eyes. My husband has green eyes. One of my children has dark gray eyes (not blue, not green, not brown) and the other child has greenish/light brown eyes. Very strange combos.
This would certainly explain how my brother and I both have blue eyes but a different shade from our blue eyed mother and green/brown/hazel eyed father. Our eyes are darker blue than our mother's. Hers are almost clear/translucent.
I didn’t have any kind of accident, however my pupils are naturally very dilated. To see my eye color, I would almost have to look at the light. LOL That also explains my sensitivity to light.
What is even stranger my mom is brown hair, brown eyes, dad blue eyes brown hair. I was born with blonde hair and blye eyes, now I have dark bown hair and hazel eyes.
He would be the perfect antichrist in the Left Behind movies.
Isn’t that interesting? My eyes, like your grandparents’ are such a light blue that they are often described as “clear”. The light doesn’t bother me overmuch, though my son (the one with my eye color) IS bothered by it, and his pupils are indeed much larger than mine, but I doubt anyone would describe them as being unnaturally large.
Regards,
Yes it is possible, in fact there are pockets of Chinese that have blue eye and green eyed children. In either case whenever you have the genetic potential to do something generally in a large population someone will.
Yes it is possible, in fact there are pockets of Chinese that have blue eye and green eyed children. In either case whenever you have the genetic potential to do something generally in a large population someone will.
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