Are Blue Eyes Endangered?


Despite the apparent prevalence of the trait
among swanky crooners and British spies and creepy old creatures who just hung onto the
ring for too long, only about 8% of the world’s human population has blue eyes. Here in the
U.S. it’s about twice that, but that’s still a lot less than it was at the turn of the
twentieth century when nearly half of all Americans had the trait. So what happened?
Are blue-eyed humans going the way of the dodo? Well, no. We cleared up that rumor about redheads
going extinct; the same goes for blue eyes. While the trait is becoming more rare, it’s
unlikely it will disappear all together. Which is crazy when you consider that 10,000 years
ago blue eyes didn’t even exist. In fact, there’s a good chance that blue-eyed people
may all share one common ancestor. Studies over the past decade have actually traced
the trait to a mutation that most likely arose among brown-eyed people in a single human
in the Black Sea region of southeastern Europe between 6,000 and 10,000 years ago. The mutation affected what’s known as the
OCA2 gene, which helps our bodies produce melanin, the brownish pigment that gives color
to our hair and eyes and skin. The mutation created kind of a dimmer switch for the pigmentation,
but it didn’t affect the entire gene. Instead, it only affected the production of melanin
in the iris, the ring structure around the eye that regulates how much light gets in. The bulk of the iris is a thick layer of melanin-producing
cells called the stroma. And the OCA2 mutation turns the production of melanin in the stroma
way down, but the pigmentation still shows up elsewhere, like in the hair and skin and
other parts of the iris. Basically, the mutation keeps the stroma from being brown. So why blue then? Well, strictly speaking,
blue eyes aren’t actually blue. Instead, in people with this mutation, the stroma is full
of nearly colorless cells. And when the light strikes them, they scatter the wavelengths
back out, in a process similar to what makes smoke or fog look blue when light passes through
them. If there is some yellowish pigment in the
stroma, then the blue light will combine with that to make green. Throw in a little bit
of brown, and you have hazel. So how did we go from having no blue-eyed
people, to hundreds of millions of them in less than 10 millennia? No one’s entirely
sure why the trait spread so quickly through Europe. Some scientists think the mutation
could have helped prevent certain eye disorders related to long, dark northern winters. But another factors appears to be that, for
whatever reason, lots of blue-eyed people simply mated with other blue-eyed people in
the past, which kept the trait in circulation. Because for each of your genes, you have two
different versions, called alleles, one from your father and one from your mother. If you
have at least one dominant allele for a gene, that’s the trait you have. The blue eyes come from a recessive allele,
which means if you inherit one allele for blue eyes and another for brown, you’re going
to have brown eyes. But you still carry the recessive blue allele, which can be passed
on. Which means that that first person that had that blue-eyed mutation didn’t have blue
eyes. They had to pass that onto their children, and their children had to pass it onto their
children, until eventually they came back together to make someone with two blue-eyed
alleles. When both parents have blue eyes, they both
have two recessive blue-eyed genes, which means their children will also have blue eyes
since there’s no dominant gene to mask the recessive one. This is how you end up with
Scandinavian countries that are 95% blue-eyed, and it also explains why the percentage of
blue eye-ers is dropping in much of the western world. Human populations are a lot more evenly spread
throughout the world than they were 10,000 years ago, so more blue eyes are pairing up
with brown eyes and producing brown-eyed offspring. I wouldn’t go so far as to call them endangered,
but safe to say those blue-eyed singers and spies and Gollums will always be in the minority. Thanks for watching this SciShow Dose. If
you’d like to help us keep exploring the world, just go to subbable.com/scishow to find out
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100 comments

  1. I have blue eyes and so does my spouse and our kid has greenish light colored eyes. He is mine, I’ve done a paternity test, and the doctors said it’s not a given that two blue eyed parents will have a blue eyed kid. I’m kinda disappointed. I love my kid of course but his eyes are weird colored.

  2. Is anybody half black and half white with tan Italian skin, with blonde hair and blue eyes, cause i think it’s just me

  3. Blue eyes are endangered. Click my account and go to my "war against blue eyes -Whites" playlist.
    Lost of videos of choosing.
    Feel free to read the description of the playlist.

  4. Wait wait wait…..my mother has brown eyes and my father has blue……so how did I get my pops blue eyes?……I should have brown eyes right?

  5. My dad has brown eyes my mum has blue eyes and I have blue eyes how come I have blue eyes if your support to have brown if one of your parents have brown eyes

  6. My cousin has brown hair, brown eyes, mated with a brown hair, brown eyed spouse and produced blond hair, blue eyed kids.
    They both carried the blue eyed gene, one from my grand mother, the other from the spouse’s parent. So why does it seem like this gets explained as if the brown alios dominate the blue alios ? When does the dominating happen? It seems it happens when a brown alio reproduces with a blue alio and then the only choice is the production of a brown eyed baby, but this doesn’t account for the brown eyed parent having a blue eye recessive gene. Is it that the only thing that is for sure is that two blue eyed parents can only produce blue eyed offspring?

  7. 3:20 says it all. Not going extinct, but will become more and more rare… Oddly due to "diversity", or at least what idiots have been brainwashed into thinking diversity is.

  8. No I don't think so because my parents have brown eyes and green eyes and I have blue eyes so how is that the only person in my family who has blue eyes??

  9. Nah man, blue eyes are gonna become common, especially since brown eyed guys like me who LOVE colored eyes like blue and green.

    Yes, I'm almost for sure my children are gonna be blue; I'm part German.

  10. Guy in video: blue eyed people may have a same ancestor

    Me and my girlfriend who both have blue eyes..:

    SWEET HOME ALABAMA

  11. blue eyes is not endangered because I have it as a indian big deal woopdeedoo! who cares  what matters is white uglys will be endangered because twothirds of the global population don't like you nor want you on our earth.

  12. My father's eyes are dark brown and my mother's eyes are a light blue that actually looks colorless in the sun. I have dark and light grey rings with a bit of green and brown colors near my pupil 😂😂🤔🤔

  13. I have blue eyes and all my family members have brown so what does that mean for me? Am I adopted or just special?

  14. The mutation spread via sexual selection. It can't perish, just became a less attractive trait. But to possibly had prevented eye disorders? Blue iris has all the trouble with assessing contrast differences, disability glare etc.

  15. 1:44 that's same as saying leaves aren't green, they just have green pigment in them that make them green. If they are reflecting blue light, aren't they just blue. I mean, everything has its colour because they reflect a specific colour of light, right?

  16. The percentage of blue eyed people in the US has dropped because the immigrants coming into the country are no longer mostly from Europe but non-blue eyed areas of the world like Asia and Latin America.

  17. We are gonna have to do our part to stop the blue eyed population dying out..after all..we're to sexy to become extinct.

  18. My wife is Puerto Rican with brown eyes, we have 1 boy and 2 girls, our son (the oldest) and youngest daughter both have blue eyes.

  19. The liberals in this world preach diversity and the protection of minorities ,
    and yet they seem to intend the extinction of any population
    that is not brown eyed and black haired and dark skinned .

  20. Here is a question for you. If black skin and brown eyes are dominant how can the population of all these people with them be breed from 1 common ancestor? Impossible and you know it. Now here is another question if black skin is dominant why are African Americans getting lighter skin to Africans & why are Aribs nearly white now? Ever think someone is not telling you something or not as clever as they make out? That is what these video on YouTube make me think.

  21. What are chances of being born? Doubt that can be quantified. Close to "miracle" as you can get?

  22. Blue eyes means recessive genes , its a sign to say ; i have recessive genes i want be around very long GOD may have Cursed me ??

  23. My brother has blue eyes and black hair, my mom has green eyes and black hair.
    My dad and I both have murky brown eyes.
    (Scandinavia is inbred)

  24. I have a dark blue left eye and an electric blue right eye
    If u don't know what electric blue looks like look at the sky at midday. It looks like that.

  25. The difference now is that they'll be a minority in their own countries, thanks to globalism. Plus populations aren't spread out over the world, it's only in western countries where globalists and progressive allies have and want to open the borders to the third world.

  26. ……….strange how it takes millions of years for humans to evolve yet only ten thousand years for blue eyed white people to evolve.
    …….blue eyed white people are under treat of extinction by Semite agendas aimed at destroying white blue eyed Northern European people's.

  27. Ok so having blue eyes is not the real thing, its just a mutation, and they are not blue, they are colorless cells

  28. Blue eyes arent most rare. I have em and I like them but of course evryone wants what they cant have. It's not like people with blue eyes have more fun. I know the expression is supposed to be about blondes

  29. When the population of bald eagles was decreasing and showed no signs of reversing, they were called endangered. When the population of certain whales was decreasing and showed no signs of reversing, they were called endangered.

    As the population of people who have blue eyes continues to decrease, and the trend shows no signs of reversing, this very intelligent man who is also a fool, says don’t worry about it. They’re not endangered. They will just “always be in the minority.”

    I guess when blue eyed people have been totally bred out of existence, a future genius can do another video explaining how the number zero is really just an extreme case of being “in the minority.”

  30. Well practically all blue eyed people are white, so we can safely say white people are endangered. Non-whites in Europe are increasing in numbers.

  31. Wait so if one of your patterned has brown yes and another has blue that means you automatically have brown eyes bit confused cause one of my Parents are brown and the other is blue and I have a blue ?

  32. Could you do an episode on central heterochromia?? I have blue eyes with a ring or green around the center. I know there are other combinations as well. How does that happen?? How many people have it? And how many people with predominantly blue eyes have it??

  33. Mine are blue green. Anti white agenda happening right now to exterminate us. Breed in your own group and continue your beautiful genes! Don’t be race traitors

  34. There is a lapse in this video (a very large lapse)! Between 8000 and 10,000 years ago (at least), ALL Western Europeans had blue eyes: they were the Mesolithic western hunter-gatherers (WHG). Modern Northern Europeans have the highest WHG ancestry of all Europe (and the highest percentage of blue eyes also). The Black Sea theory does not appear to be the true origin of blue eyes in Europe.

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