Originally posted by Mr_skepticc
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.
I found this very intresting, because I do have blue eyes, and everyone in my immediate family do as well. They just don't know why the original blue
eyed ancestor had blue eyes, very odd. Everyone had brown eyes, but something happen.
Read more about this, it's fascinating!
www.sciencedaily.com...
It doesn't quite explain all blue eyes. There's actually 3 alleles on 2 chromosomes known to give eye color. And there's 2 types of blue eyes.
There's blue eyes that a blue and blue all the way through. And there's blue eyes with an amber star pattern around the pupil.
Blue eyes all the way through and through are
Chromosome 19: EYCL1 = blue, blue
Chromosome 15: EYCL2 = blue, blue
Chromosome 15: EYCL3 = blue, blue
Blue eyes with the amber star pattern around the pupil like the
blue eye on Wikipedia
are ...
Chromosome 19: EYCL1 = blue, blue
Chromosome 15: EYCL2 = blue, amber star
Chromosome 15: EYCL3 = blue, blue
Green eyes are....
Chromosome 19: EYCL1 = blue, green
or green, green
Chromosome 15: EYCL2 = blue, blue
Chromosome 15: EYCL3 = blue, blue
Brown eyes are any of the following combinations ...
Chromosome 19: EYCL1 = blue, green
or blue, blue
or green, green
Chromosome 15: EYCL2 = blue, amber star
or amber, amber
or brown, amber
Chromosome 15: EYCL3 = blue, brown
or brown, brown
So it is possible for two brown eyed parents to have a blue eyed kid or a green eyed kid. But it's NOT possible for two blue and blue eyed parents
(blue through and through) to have a brown eyed kid or a green eyed kid. Blue through and through have nothing to give but recessive blue genes on all
alleles and chromosomes.
Hazel eyes are more complicated and their might be a 4th allele on another gene also related to hazel eyes or combination color eyes.
Bi-color hazel eyes are ...
Chromosome 19: EYCL1 = green, green
Chromosome 15: EYCL2 = blue, amber star
Chromosome 15: EYCL3 = blue, blue
Tri-color hazel eyes are ...
Chromosome 19: EYCL1 = blue, green
Chromosome 15: EYCL2 = blue, amber star
Chromosome 15: EYCL3 = blue, blue
But like I said before on hazel eyes, there still might be another allele related to eye color on another gene causing mixing in colors.
So...one mutation just doesn't explain the wide variety on at least 2 chromosomes and 3 different alleles. There's got to be more to it.
Answering Rare Questions about Eye Color Genes
Eye Coloring Genetics (powerpoint)
