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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: SunkenCiv

As a kid my eyes were blue like top center but are not green likd middle left.

When in my twenties my eyes were stil blue, but when I drank they went very green.


81 posted on 05/31/2009 3:17:30 PM PDT by School of Rational Thought (I once had an awkward moment just to seen how it felt.)
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To: Pharmboy

All of my siblings and parents (7 total) have center top blue. I have center...green, I guess.


82 posted on 05/31/2009 3:24:23 PM PDT by bannie
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To: ReagansShinyHair
The Black Muad'Dib ? Could he be the One ? ;-)
83 posted on 05/31/2009 3:30:06 PM PDT by fieldmarshaldj (~"This is what happens when you find a stranger in the Alps !"~~)
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To: chuck_the_tv_out
It's either 74%, or it's not 74%. It might be "about 75%", but "about 74%" is pure tardedness.

"About 74%" is a perfectly legitimate way to express a more precise number like 73.89%.

84 posted on 05/31/2009 3:54:29 PM PDT by wideminded
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To: Jemian

I would have had a hard time believing it myself, but it happened to ME!


85 posted on 05/31/2009 3:59:38 PM PDT by Pharmboy (Who ever thought we would long for the days of the Clinton administration...)
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To: Larry Lucido; Perdogg

Well, it does give the night bright colors.


86 posted on 05/31/2009 4:03:29 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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To: EyeGuy
The article also sez this:
"Green eyes probably represent the interaction of multiple variants within the OCA2 and in other genes, including perhaps the red-hair gene," Duffy says.
:') Hair color is in that boat -- that is, true red hair has a different color, while everyone else (other than albinos I suppose) has varied levels of a single pigmentation. Maybe that's why the guy suggests that.
87 posted on 05/31/2009 4:06:49 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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To: Monkey Face

What good would that do anyone? ;’) Probably red hair and green eyes depends on having two X chromosomes...


88 posted on 05/31/2009 4:08:30 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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To: MyTwoCopperCoins

...or so the dad likes to think. ;’) Probably atavistic, from one or both of their sides of the family, white ancestors in the woodpile.


89 posted on 05/31/2009 4:09:42 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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To: SunkenCiv

*snort*

If yore purdy, it don’t matter none. ;o]


90 posted on 05/31/2009 4:10:31 PM PDT by Monkey Face (Is a vegetatian permitted to eat animal crackers?)
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To: srmorton
Eye color is an example of what biologists call "continuous variation" - a trait that is obviously influenced by multiple genes. I always remind my students that this is the case even while I am using eye color as an example of a simple Mendelian trait.
Well, that's just mean. ;') ;')
91 posted on 05/31/2009 4:10:43 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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To: Pharmboy
Celtic, Romanian, Jewish and Ukrainian
Hey, at least it rhymes.
92 posted on 05/31/2009 4:11:18 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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To: Pharmboy

Kinda makes it hard to refute, doesn’t it?


93 posted on 05/31/2009 4:13:26 PM PDT by Jemian (PAM of JT ~~ Caligula, just like his Kenyan ancestors, is selling his countrymen into slavery.)
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To: SunkenCiv
I'm #3. My father was #9 (German and Irish), and my mother #4 or #5 (German and Irish). My husband is #2 (Swedish, Scottish and Irish)
94 posted on 05/31/2009 4:15:21 PM PDT by trisham (Zen is not easy. It takes effort to attain nothingness. And then what do you have? Bupkis.)
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To: MyTwoCopperCoins

Wow!


95 posted on 05/31/2009 4:16:28 PM PDT by trisham (Zen is not easy. It takes effort to attain nothingness. And then what do you have? Bupkis.)
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To: svcw

Must be some extraterrestrial DNA... [spooky organ sounds]


96 posted on 05/31/2009 4:16:47 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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To: Red_Devil 232
404
97 posted on 05/31/2009 4:21:36 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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To: School of Rational Thought

I’m just glad I’ve *got* eyes. Although it would be cool to have Steve Austin’s $6 million dollar man eyes...


98 posted on 05/31/2009 4:23:20 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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To: trisham

Oh I see, numbering the different examples above... I’m not even on there, just noticed this. I’m darker than the darkest, like rich columbian coffee. Or manure, depending on what I’ve just said to somebody...


99 posted on 05/31/2009 4:24:48 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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To: chuck_the_tv_out; raybbr; Ole Okie; Hyzenthlay
I'm glad that's settled. ;')
Pierre Teilhard de Chardin

100 posted on 05/31/2009 4:27:45 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/____________________ Profile updated Monday, January 12, 2009)
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