Everyone with blue eyes, raise your hand.

[Bronco Bob]

If you have blue eyes, you may be related to every other blue-eyed person in the world.

Researchers in Denmark have found that every person with blue eyes descends from just one "founder," an ancestor whose genes mutated 6,000 to 10,000 years ago. Before then, everyone had brown eyes.

Lead scientist Hans Eiberg, a geneticist at Copenhagen University, began in 1973 to study a Danish father with 17 children who carried the gene for both blue and brown eyes. Over time, researchers were able to trace the blue-eyed trait to one specific area near a gene called OCA2. The paper appears in the journal Human Genetics.

Eiberg's team then tested 155 blue-eyed people from Scandinavia, Turkey, Jordan and India, looking to see whether they, too, had similar DNA sequences on that gene. To their amazement, they found that each individual had identical DNA sequences in that region of that gene, an indication that the original mutation happened recently enough that it hasn't had time to change.

Everyone has two genes for eye color, one from their father and one from their mother. Brown eyes are dominant, so even if someone has one blue and one brown-eye gene, he'll still have brown eyes.

That means that the recessive genes for blue eyes can be invisible for generations, with blue-eyed children popping up only when both parents carry at least one blue-eye gene, Eiberg says.

Blue eyes are actually what happens when the human default — brown eyes — is turned off. Brown eyes are caused by the pigment melanin, which also gives color to hair and skin, building up in the eyes. It's why many light-skinned babies are born with blue eyes but gradually develop brown eyes as their body produces melanin in their irises. The blue-eye mutation turned off the gene that produces melanin in the eyes.

When the original mutation occurred, the person who carried it would still have had brown eyes, says Eiberg. But in the generations that followed, a man and a woman who each had one blue-eye gene mated, producing the world's first blue-eyed baby.

Imagine what a surprise that was, Eiberg notes. "If the child was the only one to have blue eye color and everyone else has brown, it could have been very interesting."

That one mutation now exists in an estimated 300 million people, Eiberg says. Why it has become so common in some populations is unknown. It has been suggested that blue eyes and the lighter coloring that often accompanies them might have given an advantage to people in colder climates because they could absorb more vitamin D from the sun. Others have suggested it's simply a roll of the historical dice, with the original group that had the blue-eye genes coming through a genetic bottleneck.

"Maybe the population almost went extinct. If just a few individuals survived at some point and they were blue-eyed," then it could have happened much more recently, says Klaus Kjaer, a geneticist at the University of Copenhagen who also worked on the paper.

Blue eyes, though somewhat rare in the USA, are common in countries near the mutation epicenter, which previous researchers have pinpointed as probably somewhere in the Balkans or near the Black Sea.

In Estonia, 99% of people have blue eyes, Eiberg says. In Denmark 30 years ago, only 8% of the population had brown eyes, though through immigration, today that number is about 11%. In Germany, about 75% have blue eyes.

Because the research shows that all blue-eyed people are related, Kjaer notes it's "interesting" that his blue-eyed wife is therefore related to Brad Pitt.

http://www.usatoday.com/news/health/...lue-eyes_N.htm

{In the interest of disclosure, I have brown eyes, so I'm probably not that closely related to you}

[L.A. BRONCOS FAN]

(Raises hand)

Very interesting.

[Rigs11]

My eyes are brown, cuz I'm full of shet

[Spider]

Green eyes .and a damn good dancer ....even Iam the only one that thinks so

[TDmvp]

sigh ... i have blue eyes.... and i call bull$hit on this ... I am not releated to L.A lol

[ak1971]

/

[BroncoBuff]

Green count?

[L.A. BRONCOS FAN]

Originally Posted by TDmvp

sigh ... i have blue eyes.... and i call bull$hit on this ... I am not releated to L.A lol

Now that's a scary proposition.

[TDmvp]

Originally Posted by L.A. BRONCOS FAN

Now that's a scary proposition.

:O)

[snowspot66]

Originally Posted by BroncoBuff

Green count?

Yep, same mutation I believe.

[Meck77]

Well my eyes are green and brown. So is that a spin off of the same mutation?

I was cool with the idea that most of you wear orange from time to time. That is as close to family as I'd want some of you to be.

[orinjkrush]

blue here. incest is best.

[Spider]

Originally Posted by Meck77

Well my eyes are green and brown. So is that a spin off of the same mutation?

I was cool with the idea that most of you wear orange from time to time. That is as close to family as I'd want some of you to be.

, my wife had 1 brown and 1 green eye

[orinjkrush]

my brother has two GOLDEN eyes. 'course his DNA sequencing from NAT GEO came back as "of unknown origin"
scary to look at. too bad he couldn't get some of the royalties.

[Sassy]

My dad has brown, My mom has green and I have blue.
I got my "startling, intense" blue eyes from both Grandpas...my sisters both have brown eyes.

I'm good then...H has brown eyes

[ant1999e]

Blue eyed freaks!

[Kaylore]

Hazel here. I wonder where my mutation occurred and if it will unlock secret powers to enable me fight evil.

[alkemical]

Mine are hazel, but they change to gold & green allot.

[TheDave]

Raises Hand...

Lucky me I got blue eyes AND red hair... I'd like to figure out who my common ancestor is so i can give thanks by desecrating their grave

[That One Guy]

I've always heard something about either brown eyed people could've have blue eyed babies or the other way around... but it sounds like two brown eyeds could have a blue if both were recessive but happened to be what passed on... right? So much for street geneticists...

[Rohirrim]

My oldest son has blue eyes. My wife and I both have brown eyes, ergo, we both must carry the recessive gene, right?

[W*GS]

Wife is hazel, I'm blue, two kids with blue, one with brown.

Eye color is more complicated than just brown/blue, of course.

[Spider]

My kids 4 0f them blue , 2 green ......

[BroncoBuff]

Originally Posted by BroncoBuff

Green count?

Originally Posted by snowspot66

Yep, same mutation I believe.

Well then WELCOME TO THE FAMILY, EVERYBODY!!

[Bronco Bob]

Originally Posted by cah412

I've always heard something about either brown eyed people could've have blue eyed babies or the other way around... but it sounds like two brown eyeds could have a blue if both were recessive but happened to be what passed on... right? So much for street geneticists...

Two blue eyed parents can never have brown-eyed children.
Everyone has two genes for eye color, one they get from their father
and one from their mother. So there are four combinations you
could have, Brown-Brown, Brown-Blue, Blue-Brown, or Blue-Blue.
The blue eyed gene is recessive. So it you get one gene for blue eyes
and one gene for brown eyes, you will have brown eyes. In other
words you need to get both blue eye genes to have blue eyes, Blue-Blue.
So if the man and the woman both have blue eyes, all the children will
have blue eyes. Blue-Blue + Blue-Blue (Unless the woman was fooling
around with a brown eyed man on the side). Because Blue-Blue + Brown-Brown
means the child will always have brown eyes, and with Blue-Blue + Brown-Brown
there is a 1 in 4 chance the child will have brown eyes.
With two brown eyed parents with the recessive blue eyed gene
there is an even chance the child will have blue eyes. Any combination of
Blue-Brown + Brown-Blue, Blue-Brown + Blue-Brown, or Brown-Blue + Brown-Blue
will work. But again if one parent is Brown-Brown, the children
will always have brown eyes.
The blue gene is unique - green, hazel, and other colors are just variations on
brown.