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Eye Color Explained: Everything you know is wrong
Discover Magazine ^ | March 13, 2007 | Boonsri Dickinson

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 ...


TOPICS: History; Science; Travel
KEYWORDS: blueeyes; freckles; gingergene; godsgravesglyphs; helixmakemineadouble; mutation; neandertal; neandertals; neanderthal; neanderthals; redhair
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To: Pharmboy

My eyes are hazel too (as are my Dad’s and one brothers—Moms were light brown, my sister has dark brown and one brother has blue). Kind of a weird mixed up group. However, I have noticed my particular eye color to be fairly common in friends who are half hispanic/half white.


41 posted on 05/31/2009 2:13:00 PM PDT by brytlea (Jesus loves me, this I know.)
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To: svcw

My Mom’s eyes were brown, but as she got older they got kind of goldy brown. I thought that was odd.


42 posted on 05/31/2009 2:13:59 PM PDT by brytlea (Jesus loves me, this I know.)
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To: brytlea

Yes, that is the linkage.

Not a guarantee by any means, but as an example, ARMD is more prevalent in those of northern Europeans extraction, than those of Mediterranean descent. Again, due to differences in retinal, specifically macular, pigment density.


43 posted on 05/31/2009 2:14:36 PM PDT by EyeGuy
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To: SunkenCiv

Somehow, somewhere I think there’s a mom, maybe from Maury’s show, just itching to use this to ‘splain’ to the [maybe] baby daddy he’s the one.


44 posted on 05/31/2009 2:15:17 PM PDT by Gaffer
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To: Monkey Face

I do!


45 posted on 05/31/2009 2:15:31 PM PDT by Unassuaged (I have shocking data relevant to the conversation!)
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To: brytlea

Well, maybe we’re long-lost cousins!


46 posted on 05/31/2009 2:16:06 PM PDT by Pharmboy (Who ever thought we would long for the days of the Clinton administration...)
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To: brytlea; Lil'freeper; Bender2

The only thing I know about eye color is that mine are brown and my wife says that is why I am often full of ...well you get the picture.


47 posted on 05/31/2009 2:18:27 PM PDT by big'ol_freeper ([Advocate for] Mitt Romney[?], God help you, but you're on the wrong website ~ Jim Robinson)
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To: EyeGuy

That’s good to know. My husband has blue eyes as do 2 of my sons, so they should be sure to be checked regularly, I would guess. Thanks for the info.


48 posted on 05/31/2009 2:18:36 PM PDT by brytlea (Jesus loves me, this I know.)
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To: Monkey Face

You have no Idea of the embarrassment when I sit with my family and the only people not Grey or strongly headed that way are me and the grand kiddies.


49 posted on 05/31/2009 2:19:03 PM PDT by Little Bill (Just a Poor White Person , clinging to God, Guns, and the Constitution)
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To: Pharmboy

Oh more than likely! I’m a mongrel, so it could well be. :)


50 posted on 05/31/2009 2:19:15 PM PDT by brytlea (Jesus loves me, this I know.)
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To: big'ol_freeper

LOL and probably true, yes?


51 posted on 05/31/2009 2:19:55 PM PDT by brytlea (Jesus loves me, this I know.)
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To: brytlea

Mom, dad and all my siblings have brown eyes. My grandpa (mom’s dad) had brown eyes but my grandma (mom’s mom) had blue eyes. I have green eyes.


52 posted on 05/31/2009 2:20:45 PM PDT by rintense (Senior Marketing / IT / UX architect unemployed and looking for work. Freepmail me if you have leads)
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To: Unassuaged; Little Bill

YES! OKden! Two of you...out of how many miuyons and miuyons of people in this primordial soup?

(Life is GOOD!)


53 posted on 05/31/2009 2:21:53 PM PDT by Monkey Face (Is a vegetatian permitted to eat animal crackers?)
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To: rintense

Are they green green or hazel? My husband has sort of blue green. Mine have brown in the middle and then green around that.


54 posted on 05/31/2009 2:22:43 PM PDT by brytlea (Jesus loves me, this I know.)
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To: Crazieman

My eyes are dark blue with the yellow ring. My youngest sister has gray eyes,too.


55 posted on 05/31/2009 2:23:00 PM PDT by chris_bdba
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To: Little Bill

Yes...I do. I look SO much younger than my brothers that people who don’t know me mistake me for their daughter!!

LOL!


56 posted on 05/31/2009 2:23:09 PM PDT by Monkey Face (Is a vegetatian permitted to eat animal crackers?)
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To: EyeGuy

I had very dark brown eyes until I got Pink Eye in December. After using the drops my eyes turned different colors. Sometimes they are green and sometimes they are brownish-green. I wish I had my brown eyes back.


57 posted on 05/31/2009 2:24:41 PM PDT by Shire
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To: brytlea

They’re pretty much green green now. Only a tiny bit of brown left. Didn’t really notice it until I saw up close pics of my eyes. But, when I was younger, my eyes would look more green depending on the color clothes I wore. I have mood eyes. LOL!


58 posted on 05/31/2009 2:27:25 PM PDT by rintense (Senior Marketing / IT / UX architect unemployed and looking for work. Freepmail me if you have leads)
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To: Monkey Face
The hands and face tell all. As a guy not being gray at my age is either vanity or genetics.
59 posted on 05/31/2009 2:27:56 PM PDT by Little Bill (Just a Poor White Person , clinging to God, Guns, and the Constitution)
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To: rintense

LOL and you know what green means......


60 posted on 05/31/2009 2:28:16 PM PDT by brytlea (Jesus loves me, this I know.)
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