Hmmm... are thehe Afghan girl's eyes green, ergo no single, common ancestor, or is there some blue in there?
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.”
Huh, I thought he had brown eyes.
Sorry, obviously got that mixed up. You presumably carry two copies of the blue gene. Your wife presumably carries one. As others have said, you have 50/50 chance of blue/brown eyed kids.
Adam and Eve’s mailman had blue eyes?
Interesting. Both my parents have brown eyes as do my siblings yet I have blue eyes and I am the 4th child. The 5th child got brown eyes.
Someone figure the math out for me also on this.... We have six children, husband and I both have green eyes, 5 children have blue and one brown. Why did we not get one green eyed? Are they all mine!?? LOL
LOL...!!
My Dad had brown eyes, Mom had blue eyes...
both brothers were blond hair and blue eyes!!
me...redhead with green eyes....
“Wait...so if two blue eyed people get it on...it’s incest?”
I don’t think it counts after 2nd cousin.
Adam.
No news here.
...Or 75% chance of being the Mailman's kid.
Blue on blue, heartache on heartache
Blue on blue now that we are through
Blue on blue, heartache on heartache
And I find I can’t get over losing you
.
Okay, so was my white lie really the truth or is it impossible for two blue-eyed parents to have a brown eyed son?
p.s. The guy finally became a Jehovah's Witness and that helped settle him down but didn't really stop his grumbling.
So if my aunt has three daughters, the third one is legal?
"In addition to future medical applications, the data are also of interest to anthropologists who study historical human migrations. The Southern grouping included individuals from Greece, Italy, Portugal and Spain, as well as Ashkenazi and Sephardic Jews. The Northern group included people with English, Irish, German, Swedish and Ukranian ancestry. These groups correspond to those historically divided by the Pyrenees and Alps mountain ranges.
Apple vendor.
Oh! There’s a heart-throb!
First crush!
Yes, but he had blue eyes crying in the rain!
Now that I think of it, many of my friends have asked me if I was adopted. I always assumed they were joking..
Hmmm... are thehe Afghan girl's eyes green, ergo no single, common ancestor, or is there some blue in there?
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