Posted on 05/31/2009 1:23:07 PM PDT by SunkenCiv
What most people know about the inheritance of eye color is that brown comes from a dominant gene (needing one copy only) and blue from a recessive gene (needing two copies). University of Queensland geneticist Rick Sturm suggests that the genetics are not so clear. "There is no single gene for eye color," he says, "but the biggest effect is the OCA2 gene." This gene, which controls the amount of melanin pigment produced, accounts for about 74 percent of the total variation in people's eye color.
Sturm has recently shown that the OCA2 gene itself is influenced by other genetic components. After gene-typing about 3,000 people, Sturm found that how OCA2 is expressed -- and how much pigment a person has -- is strongly linked to three single nucleotide polymorphisms (SNPs), or single letter variations, in a DNA sequence near the OCA2 gene. That suggests a more complicated story than the blue-recessive/brown-dominant model of eye color. "For example, among individuals carrying the SNP sequence "TGT" at all three locations on both copies of the gene, 62 percent were blue-eyed," says Sturm's colleague David Duffy. By contrast, only 21 percent of individuals carrying only one TGT copy at each location and 7.5 percent of those lacking the TGT entirely had blue eyes.
Depending on the particular combination of SNPs inherited, a person can have a range of OCA2 activity that lands them on the spectrum between blue and brown eyes. What about green eyes? "Green eyes probably represent the interaction of multiple variants within the OCA2 and in other genes, including perhaps the red-hair gene," Duffy says.
(Excerpt) Read more at discovermagazine.com ...
mmmhmmm
Actually, that IS true. Advertisers of sex-based items (clothes, perfume, even make up) are more likely to change the eye color of a model to green, as green is a sign of fertility. Learned that way back in college. Whether its true now, who knows.
That's because we're a very rare find. ;-)
Hands tell more than the face. The face can prematurely age due to dry climate, whether the owner of said face smokes, uses drugs, etc. Or good genes and good care can make one appear younger.
I always check hands. They tell all. Which in one reason movie stars seldom have photos with their hands in the frame.
Oh my, that might explain my 3 kids in 3 years!
HA!
I wonder if that was true back when women routinely wore gloves? I think women in white gloves look very classy. Maybe we should bring those and lovely hats back!
Don’t believe the “green-eye fertility” thing. My green eyes were no help at all when it came to having kids. I had one and had to adopt a second.
I like golves and hats! There was always something so elegant about a woman who wore them...
My husband’s used to be brown and are now green. He works in a dark environment, and I have heard that eye color can lighten under that sort of situation.
Well shoot. Its advertising! Its all about perception. :) FYI, hasn’t helped me either. ;)
Yes, it’s so Audra Hepburn!
LOL!!
I just take what I have as something that was given.
The combination of the gift is not mine to question, but I’ll be forever grateful for the genes I have that have made me who I am!
And for all of that, I am grateful!!
My idol...Audrey. She was always gracious, refined and feminine. I wanted to be like her. I was too tall and gangly...*sigh*
Bump for later read
I love genetics! My bros and my mom got the heavy German characteristics. I got my grandma’s Welsh genes, of which I am most thankful for the skinny gene!
That should not happen.
Are you sure you just didn’t start looking at your eyes more, subsequent to your conjunctivitis? Perceived iris coloration will, of course, change with your attire and environmental conditions.
What does your optometrist or ophthalmologist have to say about the sudden iris color change?
We are such a mix of genes that trying to find anything “dominant” or semi-dominant is a job for better minds than mine!
We go back through the Royalty of Europe, and that mix is something else, again! I like to think I got the best of what there was to give. I’m not drop-dead gorgeous, but not ugly as a mud fence in a rainstorm, either.
I can handle it all!! ;o]
Re: eye color changing.
We were told in school that this doesn’t happen. But in college I began dating a young man whose eyes were totally brown. Shortly after marriage (to me!) his eyes began to change and now they’re definitely green, like mine.
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