Where'd Ya Get Those Baby Blues?

Geneticists Trace Blue-Eye Gene To Mutation From One Individual

(CBS)  From Paul Newman to Frank Sinatra to Cameron Diaz. From residents of snowy Moscow to Palestinians in Jerusalem.

Danish geneticists say everyone with blue eyes is not just related, but descended from one person, CBS News correspondent Sheila MacVicar reports.

In the basement of the University of Copenhagen, frozen in vats of liquid nitrogen are thousands of DNA samples.

"This is like our secret, our gold mine," said Prof. Jesper Troelsen, a geneticist. "We dig down and find the samples we are going to use and ask specific questions about genetics."

And this time the question was, "what makes blue eyes blue?"

"All people with blue eye color have a special fingerprint," said gene mapper Hans Eiberg.

Brown, they say, is the default color for human eyes ... produced by melanin.

Blue eyes are caused by a genetic switch, programmed to suppress the melanin. It's a genetic mutation.

And in the DNA of hundreds of blue-eyed people tested by the Danish team, they found exactly the same mutation every time.

"And what would the chances of that coming from more than one person? It has to be from one person?" MacVicar asked.

"Yes, we are very sure," Eiberg said.

The first blue eyed person was probably born near the Black Sea just 10,000 years ago when the entire population of the world was less than 50,000.

Those mutant genes spread on a wave of human migration.

Today, nearly 95 percent of Scandinavians have blue eyes.

What scientists don't know is if having blue eyes was some kind of evolutionary advantage … if blue-eyed people could see better in the low winter light of Northern Europe for example. Or, was it just about downright attractiveness?

Genetics really can turn your brown eyes blue, and now, there is a whole new answer to that question: "Where did ya get those eyes?"

[hypnotoad72]

Was it from Adam or Steve?

Or, more amusingly, were Cain and Abel blue-eyed? Or since it was Adam and Eve, their 2 boys, and utter silence for a while, was it Cain or Abel that caused the mutation when they got some hot inbreeding action with Eve?

Genesis was the only chapter that never made sense... how could it, though the concept of "original sin" makes sense... of course, the chapter also suggests we''re all inbred, but nothing''s perfect...

[tucano2]

Guess that means we''re mutants decended from interbreeding between humanoids and "Aliens".

[Syndicate]

Of course blue eyes were an evolutionary advantage. They got you laid more than the other guy ;)

[amyroy1]

Ok, this article is just silly. I don''t know one family without at least one blue-eyed person in it. I have blue eyes, but my three siblings have brown, for instance. So my three brown-eyed siblings would also be descended from this one person. Maybe some countries are comprised of brown-eyed people only, but America certainly isn''t. If you are a direct descendant of a blue-eyed person, then you are related to that one special person, whether your eye color is brown, green or bloodshot. It''s got to be a huge percentage of America''s population.

[kissamaarse]

What about green? Are they considered the same as blue? What about hazel? My eyes are very green in the center, with a brown ring around he green.

[erasmus6]

"Of course blue eyes were an evolutionary advantage. They got you laid more than the other guy ;)" posted by cbscrash07

Well I guess that is just to make up for the fact that blue eyed people are less intelligent than brown eyed people.:)

[baye13]

I have brown eyes. My Father has blue so I guess I am also related to that one blue eyes person because I am related to my father genetically(sp?) Stupid study if you ask me.

I also believe we ALL decended from the first people in Africa. Not the Biblical story.

[amazedd]

Good research, wrong reasoning. Lab-mice aren''t expected to think, anyway.

[staycalm]

Just because all blue-eyed people are descended from the same ancestor doesn''t mean that all people descended from that one ancestor will have blue eyes. Some will have brown, grey or green depending on the eye color of those who married into their family tree.

[drew30319-2009]

What scientists don''t know is if having blue eyes was some kind of evolutionary advantage %u2026
-------------------------------------

I think it''s easier to identify when somebody with light-colored eyes has dilated pupils. And I''ve always understood dilated pupils to indicate a person''s level of physiological attraction or interest.

So... if you could more easily see that a blue-eyed person is interested in you I would guess that it may give that blue-eyed trait an advantage in reproducing itself.

Just a guess but it makes sense to me!

Drew Crecente
Jennifer Ann''s Group
www.JenniferAnn.org

[michellem99-2009]

I have brown eyes. I have never seen my parents eyes..Blue is my fave color..The eyes are what color they are.

[fishinfool43]

PLEASE... step away from the crack pipe!!!!

[lheureblue]

How can you explain one blue eye and one brown eye, like my 2 cousins? How could one gene be responsible? Did they get half?

[mennowoman]

"How can you explain one blue eye and one brown eye, like my 2 cousins? How could one gene be responsible? Did they get half?"

Scientists have long known that not all the cells in your body necessarily have the same DNA. Many people have some cells with completely different DNA than other regions in their bodies. Or it could be that in one eye, the gene is switched on and in the other it is switched off. Or it could be that their phenotype is different that their genotype. Only a geneticist could tell for sure.

[otdky07]

I have blue eyes and so does my wife. The great thing about this is that if we have a child who has brown eyes, I''ll know it''s not mine right away!

[biomedart]

Ah ***...both my parents have blue eyes haha!

Great story though! Thanks for having something interesting and uplifting to bring to the table! I feel like the news has been so depressing lately.

[excoachken]

Sooooo, Mr. Smartypants, how come I don''t sing like Sinatra?

[extremophil]

So this means that we''re all descended from Paul Neuman??

[dogsoul]

What about green eyes? My wife & I have a mix of green & brown - and our daughter was born with blue eyes.... she''s also got wings and can fly.

[brianbwb-2009]

The first blue eyed person was probably born near the Black Sea just 10,000 years ago when the entire population of the world was less than 50,000.

What world has had less than 50,000 people in it? Are you counting Africa, and China, the original continents we now call north and south America, or simply Caucasia?

10,000 years to reach six billion from only 50,000 people?

Don''t think so.

[dogsoul]

"What world has had less than 50,000 people in it? Are you counting Africa, and China, the original continents we now call north and south America, or simply Caucasia? 10,000 years to reach six billion from only 50,000 people? Don''''t think so."

Huh? Ever hear of exponential growth?

[emma915]

I wonder if that first blue-eyed person was considered good luck or bad luck to his or her tribe. . . . . (Must have been good luck, ''cuz we''re still here to mutate further. ..)

[markcapik]

Wow, there are really some ill informed (read stupid) people commenting on this

First off, 10000 to six billion is easy. have you actually ever seen a FULL family tree? Each generation can easily double in size. Also, their is usually more than one generation alive at any time.

Second, have you ever seen a punnet square. You could have blue, you significant other could have green, and you could still get the very rare purple eyed child. Genetics is somewhat random. You could have a dominant and recessive gene and come up with some cool endings.

http://en.wikipedia.org/wiki/Punnett_square

Thats for all how don''t know what i am talking about.

And evolution is ran by 3 tenets:

More beings are born than could survive. (humans excluded)
These beings have variations.
Their environments are different.

So evolution says that those beings who''s variations help them survive best in their environment will have kids who most likely will keep their parents variations.

So blue don''t seem to help with survival, but maybe the progenitor had something else that did.

Okay that is enough high school science for you all. I don''t want to make your heads hurt

[oleander8]

"10,000 years to reach six billion from only 50,000 people? Don''t think so."

Try this: your Dad gives you a penny on the first day of the month, the next day he gives you 2 pennies, the next day he gives you 4 pennies, the next day 8 pennies --- and so on, for 30 days. At the end of the month you would have $5,368,709.12 - all in just 30 days.

[connapa]

To follow up on emma''s comment, the first person may have been ostracized from their group, thereby moving outward into the world. repeat this a few hundred times, and eventually you are in scandinavia. Put that together with blue eyed people only reproducing and associating with other blue eyed people, and you get what we currently have.

[rf35]

Oh, look. Another Danish study. Is that all those people do?

[rushlimpdrug]

Posted by markcapik at 11:07 AM

You made my head hurt!

Anyway, I wake up with green eyes but when I go to sleep my eyes are red.

Why is that doctor?

My friend tells me it depends on what girl he takes home as to what colored eyes he wakes up with.

10,000 years to reach six billion from only 50,000 people?

Don''''t think so.

==
That''s about 17 doublings in 10,000 years, or a doubling every 588 years. Sounds quite plausible to me.

[fain6]

DON''T FORGET THAT WHEN 2 RESESSIVE GENE ALLELE "CROSS" A PERSON CAN HAVE NO DOMINENT GENE FOR BROWN EYES EVEN THOUGH THE PARENTS MAY HAVE BROWN OR "HAZEL" EYES. I HAVE BLUE EYES, MY PARENTS HAVE BROWN EYES. AH HA! YOU SAY...WELL, 3 OF MY GRAND PARENTS HAD BLUE EYES GIVING A RECESSIVE GENE TO EACH OF MY PARENTS.THOSE RESESSIVE GENES REPLACED (BY CROSSING OVER) THE DOMINENT BROWN GENE. WHICH IS WHY MY EYES ARE BLUE.

[tiberius1701]

No one has mentioned that it is easier for brown-eyed people to become snow-blind. In northern europe during a glaciation period brown eyes would be a disadvantage.

[rushlimpdrug]

So ALL the blue-eyed people came from ONE person that was mutated?

What a KROCK of chit!

ONE person and only one could have had this mutation?

These "scientist" are the most profoundly stupid idiots on the planet.

They''ve been eating to many twinkies.

[lheureblue]

"How can you explain one blue eye and one brown eye, like my 2 cousins? How could one gene be responsible? Did they get half?"

"Scientists have long known that not all the cells in your body necessarily have the same DNA. Many people have some cells with completely different DNA than other regions in their bodies. Or it could be that in one eye, the gene is switched on and in the other it is switched off. Or it could be that their phenotype is different that their genotype. Only a geneticist could tell for sure."

The article says there''s a single mutation...and it''s an off switch, to supress the melanin. But, you''re right, perhaps there is a right or left side override mechanism in my 2 cousins. Ohmigosh, maybe this is an indicator of some inner eye irregularity?? What else is this mechanism overriding??

Why don''t they offer my cousins a free trip to Copenhagen to study them? I think there are other people out there like them. Bring them all to Copenhagen! (Sorry, something inside me has just overridden its mechanism...)