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ceebeegeeAll blue-eyed people have a common ancestor.
"Originally, we all had brown eyes," said Professor Eiberg from the Department of Cellular and Molecular Biology. "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. ...
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."
I'm related to Frank Sinatra and Reese Witherspoon and Bill Clinton and Brad Pitt...
What I would like to know is--what is the evolutionary advantage of blue eyes? Or is there one? I always thought it might have something to do with light and Vitamin D absorption and possibly a link to depression, but according to one article:
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.
"Originally, we all had brown eyes," said Professor Eiberg from the Department of Cellular and Molecular Biology. "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. ...
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."
I'm related to Frank Sinatra and Reese Witherspoon and Bill Clinton and Brad Pitt...
What I would like to know is--what is the evolutionary advantage of blue eyes? Or is there one? I always thought it might have something to do with light and Vitamin D absorption and possibly a link to depression, but according to one article:
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.
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Date: 2008-02-05 08:17 pm (UTC)You get more songs written about you.