What Causes Blue Eyes In Humans?

What Causes Blue Eyes In Humans
What Causes Blue Eyes? – Blue eyes have fascinated people for centuries. In cultures around the world, they are seen as beautiful yet also cold. Blue eyes are rare, making up just 8-10% of the world’s population. Blue eyes are caused by a relative lack of melanin in the iris.
Don’t It Make Your Brown Eyes Blue? Blue-eyed? Thank a genetic switch that turns off your body’s ability to make brown pigment in your peepers. Researchers have finally located the mutation that causes blue eyes, and the findings suggest that all blue-eyed humans share a single common ancestor born 6000 to 10,000 years ago.

Researchers have implicated the OCA2 gene in several eye colors. The gene is involved in the production of melanin, a pigment that gives hair and skin their hues. It also codes for brown eyes and can lead to green or hazel eyes when mutated. Despite years of searching, however, scientists have not found a mutation for blue eyes on the gene.

It turns out they were looking in the wrong place. Trying to narrow the site of the mutation, gene mapper Hans Eiberg of the University of Copenhagen and colleagues examined members of a large Danish family, an approach that allowed them to follow DNA as it passed from one generation to another.

  • Then, by comparing people with brown or blue eyes, including people from Jordan and Turkey, the researchers were able to pinpoint the exact mutation.
  • It wasn’t on the OCA gene but rather on a nearby gene called HERC2,
  • The mutation works like a switch that regulates the OCA gene, the team reports in the January issue of Human Genetics, turning off the production of brown eye color and allowing blue eyes to shine through.

Because blue eye color is found almost exclusively in people of European descent, Eiberg’s team speculates that the mutation traces back to the Neolithic expansion, when people in the Black Sea region migrated to northern Europe 6000 to 10,000 years ago.

Two other studies, both appearing in this month’s issue of The American Journal of Human Genetics, examined blue eyes in different populations and found the same mutation. The researchers also suggested a common ancestor for all blue-eyed individuals. These teams, however, did not estimate an age for the mutation.

Geneticist Richard Sturm of the University of Queensland in Brisbane, Australia, an author of one of the papers says that someday scientists may find additional mutations that cause blue eyes but for now, the signs point to a single change. Sturm says that it’s not uncommon for one gene to regulate another, but it is difficult to locate the mutation in the controlling gene.

  • One of the most cited examples is the mutation involved in lactose tolerance, which is also caused by regulation from outside the gene.
  • Sturm says that such regulating genes may contribute more to genetic diversity than previously thought.
  • The findings also have applications in forensics.
  • Geneticist Manfred Kayser of the Erasmus University Medical Center in Rotterdam, the Netherlands, an author of the other paper that appears in The American Journal of Human Genetics, says if police fully understood mutations behind eye color, for example, then they could use them to determine the eye color of a suspect based solely on DNA evidence.

Geneticist Tony Frudakis of DNAPrint Genomics Inc., a Sarasota, Florida, company that develops genetic-testing products, is shocked that the mutation happened just once. Although there are about 10 ways to get someone with red hair, the scientists found only one way to get someone with blue eyes.

I would have thought blue eyes arose several times independently,” Frudakis says. There are still large questions, though. Why did blue eyes persist? Scientists say it is difficult to see how eye color would have an environmental advantage, as skin color does. Some theories suggest that women may have played a role in driving the selection.

Perhaps, Kayser says, “the females thought it more exciting to have a male with blue eyes.” Related site : Don’t It Make Your Brown Eyes Blue?

Why do blue eyes have melanin?

5. Risks associated with blue eyes – Melanin in the iris of the eye appears to help protect the back of the eye from damage caused by UV radiation and high-energy visible (“blue”) light from sunlight and artificial sources of these rays. Because blue eyes contain less melanin than green, hazel or brown eyes, they may be more susceptible to damage from UV and blue light.

Regarding connections between eye colour and eye diseases, research has shown darker iris colour is associated with an increased risk of cataract and a reduced risk of ocular uveal melanoma (a form of eye cancer), compared with blue eyes. But the same analysis of published studies failed to confirm any association of eye colour with increased risk of age-related macular degeneration (AMD),

Still, because many people with blue eye colour are sensitive to light and may have more risk of damage to their retinas from UV light, most opticians recommend that people with blue eyes should be extra cautious regarding their exposure to sunlight.

And because eye damage from UV and blue light appears to be related to your lifetime exposure to these rays, wearing sunglasses that block 100 percent UV and most blue light should begin as soon as possible in childhood. Photochromic lenses are another great way to protect blue eyes from UV radiation.

These clear lenses block 100 percent UV both indoors and outside, and darken automatically in response to sunlight when you go outdoors so you don’t have to carry a separate pair of sunglasses. Also, adding an anti-reflective coating to photochromic lenses gives you the best vision and comfort in all lighting conditions (including driving at night ) while showcasing your blue eyes with reflection-free lenses.

  • AR coating is recommended for all types of glasses lenses — including single vision, bifocal and progressive lenses — to eliminate distracting reflections and allow people to see the beauty and expressiveness of your eyes.
  • Also, if you spend several hours a day using a computer, smartphone or other digital devices, it’s a good idea to wear spectacles that shield your eyes from high-energy blue light when using these devices.

It may take many years before we know the risks associated with cumulative exposure to blue light from computers and smartphones, but many eye care professionals believe it’s prudent to use caution when it comes to protecting your eyes from these devices — especially if you have blue eyes.

  1. SEE RELATED: Computer vision syndrome & digital eye strain: Symptoms & treatment A final note about blue eyes you might find interesting: Research suggests that having blue eyes may increase your risk of alcohol dependency if you are a drinker.
  2. A study of European Americans with blue eyes found people with these characteristics had up to 83 percent higher odds of becoming dependent on alcohol, compared with matched controls who had darker eye colour.

FIND AN OPTICIAN OR OPTICAL SHOP NEAR YOU : Our locator lists nearby opticians and optical shops to make booking appointments easy. Page published on Tuesday, 25 June 2019

Why is my Baby’s eye blue?

Why do some babies’ blue eyes turn brown? – What Causes Blue Eyes In Humans Shutterstock If you’re a parent, or are close to someone who’s had a baby, you might have had the experience of watching the eyes of an infant change color from bright blue to green or brown. That’s why you can’t know what someone’s eye color will be when they grow up until about the six-month mark, according to an article published by McGill University,

The reason that many babies are born with blue eyes that can later change to brown is, once again, due to the way melanin functions in the human body. When a baby is born, melanin hasn’t yet been fully deposited into the iris of the child’s eye, which results in the iris being blue. But after a certain period, the genetics kick in and melanin production either ramps up, changing the color of the baby’s eye, or doesn’t, rendering the color of the iris blue for life.

It’s just one more way that the human body is truly a mystery.

What is a cataract if you have blue eyes?

Cataracts – A cataract is a clouding of the eye’s lens. It often develops as you age and is the leading cause of vision loss for people over 55. If you have a darker iris color, you are at a greater risk of developing this eye disease. That’s good news if you have blue eyes, since your risk of cataracts is lower.

Why do some people have blue eyes?

More Black People With Blue Eyes – © 2016 Edmund Custers Shenna on August 14, 2020: Is called the e Eve Gene Google the Eve Gene that talks about mutated DNA and how everything came to Charles Ayara on August 08, 2020: Thank you for the very interesting and enlightening article.

Brown and blue eyes, I knew, but never knew people could also have green eyes. And many thanks to Dr Pamela Irabor for forwarding the article to my page to satisfy my curiosity. Cecilia on July 04, 2020: What I want to know is can a black person with blue eyes be called an albino? Yumnam Linthoisana on April 26, 2020: In my culture, it’s extremely rare for babies to be born with light-coloured eyes.

See also:  What Does Light Brown Eyes Mean?

The standard for beautiful eye colour is “eyes as dark as the night”. Light-coloured eyes are considered unattractive, blue eyes being considered the most unattractive. So even if a few individuals are born with light-coloured eyes due to sporadic genetic mutations, they have a much lower chance of being chosen by potential partners and passing on their genes.

  1. George on February 21, 2020: Being African American male possessing dark brown eyes and not knowing why my mother had red hair, freckles and hazel colored eyes? All of which she hated and was teased relentlessly as a child.
  2. Her mother was light complexioned with hazel eyes who had a blue eyed brother a hazel colored sister and a green eyed sister.

My genealogy is all over the place. I’d like to know what happened and why? Hadija kagimu on January 06, 2020: But in Africa we don’t consider being with blue eyes a beuty we consider big ones not the colour Doris James MizBejabbers from Beautiful South on December 29, 2019: Very interesting article.

  • Today the “experts” are saying that all of us blue-eyed people descended from one common female ancestor in the past.
  • As a child my eyes were a turquoise blue like both my parents, but for awhile my eyes turned green.
  • After my thyroid was removed, the color turned back to blue, this time almost navy blue.

We are of Celtic and French-Germanic ancestry with a little Mediterranean thrown in as shown by a DNA test. No trace of the Choctaw or Cherokee that family rumor said we were supposed to have. I have met two people in my lifetime who had yellow irises, not amber, but yellow.

They were not connected to each other in any manner and lived in different states. Lee on December 26, 2019: My father is one of 14 children, and he, two aunts, one uncle, and my grandmother (now deceased), all were born with blue eyes. His other siblings born with brown eyes. I was born with brown eyes.

We are Black Americans. Of my three kids, the two oldest were born with blues, the youngest with brown eyes, however, my wife is of German-Irish ancestry, with her grandmother having blue eyes. My two oldest kids could have inherited from either side of our families.

Edmund Custers (author) on December 21, 2019: Hi Tristan, I am glad you found the article interesting. Recent studies have shown that a person’s eye color is determined by several genes. So it is not determined by a single gene as people used to think. So based on the new model involving multiple genes, the inheritance pattern is much more complex than what you describe.

So the eye color(s) of the parents can be used to predict a child’s eye color. However, gene variations can produce unexpected outcomes. Thank you all for the comments. Tristan Lindebjerg Johansen on December 19, 2019: Very interesting article. I do though believe your colour chart is completely wrong.

Take brown (B) + blue (b): If one parent has BB and the other one bb (both homozygous) there is roughly 0% chance of getting a blue eyed baby as a result of anything else than a mutation. The other case: Bb and bb (brown, heterozygous. Blue, homozygous) there is a 25% chance of getting a blue eyed kid.

Ultimately this means that given the phenotypes of the parents, there is roughly 12.5% of getting a blue eyed baby. There will though be a 100% chance for the kid to be able to produce a blue eyed baby, when it comes to that 🙂 Karen on October 16, 2019: I have blue eyes.

My mom had blue eyes, aunt and cousin have blue eyes. My grandfather had blue eyes. My son has one blue one brown eye and his daughters/my granddaughter has blue eyes. Five generations straight that I know of. All African Americans Camilla on October 13, 2019: I have blue eyes, my mother has gray eyes my father had brown eyes.

Yes they aremy biological parents. I have 4 children with brown eyes as did my husband. I have 4 grandkids all with brown eyes. But I have cousins with blue, gray, green, amber and hazel eyes. Sid on October 11, 2019: My grandpa had light green eyes and my grandma had black They had seven children among which my uncle only has the green one Others all have brown Curtis on October 09, 2019: My mother has blue eyes.

  • Along with my aunt and my nephew has one brown eye one blue.
  • For this to be rare it’s pretty common it would seem in my family but alot of these young girls on you tube on June 18, 2019: mary johnson but allot of these young girls on you tube that are black with blue eyes say there eyes are real but just like there fake hair tutorials there eyes are not blue but blue contacts instead Asya on June 08, 2019: Also my moms mom has green eyes and my moms dad has dark blue.

She and her suster (my aunt) have brown eyes. How is it possible if here it writes that green and blue cannot make a brown eyed baby, when my grandparents made 2? Asya on June 08, 2019: But my mom has brown eyes and my dad has blue yeyes. How come i has born with green? Maya Freeman on May 29, 2019: I’ve always thought that it is very rare for a brown skinned person to have blue eyes.

  1. But, is it possible for a person’s eye clor to change slightly in between seasons? I have a friend who’s eyes seem to appear to be a different shade each season.
  2. Silvia on May 02, 2019: I also noticed the chart that says brown and blue eyed persons can’t produce a green eyed child.
  3. I remember learning this in biology class as well.

However, my mothers eyes are as blue as they get (with no hint of green really) and my dad has dark brown eyes. My dad is absolutely my biological father. No doubt. I happen to have green eyes -really green eyes, although there is a hint of yellow around my iris, there is no blue or brown.

  1. Donna S on April 05, 2019: Hi, i noticed on the chart that the brown eyed and blue eyed set of parents seem to not be able to produce a green eyed child.
  2. My brown eyed niece and her blue eyed partner produced a beautiful boy with eyes that change from teal blue to light blue to green and at times gray, at times within minutes,

My nieces father has blue eyes, her mom has brown eyes. Her blue eyed partners mom had green eyes. His father may have had green or a hazel greenish eyes. His brother has greenish eyes. I guess there are not definite genetic laws that dictate who gets what eye color.

Genetically there is a blend of Sicilian and Italian plus German and Irish and who knows what else running through everyones DNA. I also had a brown eyed Italian descent friend and her Turkish dark brown eyed hubby who had a beautiful lavender eyed baby boy. His eyes later turned to green then to brown.

Turkish grandfather had unusual bluish eyes. jo on January 07, 2019: Ra.people marvel over blue eyes because they are rare and beautiful. Thants not saying that other colored eyes are not beautiful because they are.they are just not as rare except for green eye,being recessive only explains how rare the trait is, it does not make the trait bad.

  • Ra on January 01, 2019: So sad how people marvel over blue eyes without noticing its a recessive trait.
  • A dude on November 25, 2018: Yeah, the thing with black people and yellpw eyes is usually just due to the amount of melanin they produce, not health conditions.
  • A lot of African born people have yellow scaleras, even me, but some are just a lot lighter and not very noticible or are only in certain parts of the scalera.

Ellen on October 30, 2018: I’m another one – brown-eyed mother and (very) blue-eyed father, and my eyes are green. Mother’s father had gray eyes. Since I look like my father and his whole family, I don’t doubt parentage. 🙂 Teresa kane on October 22, 2018: They say if one parent has blue and one has brown their child cant have green eyes thats not true because Im livivng proof my bio mom had brown eyes and my bio father has blu eyes and I have green eyes me and my two kids are the only one has green eyes in four generation of our family I dont under stand why Brandon on October 21, 2018: Everyone is amazed that my eyes are dark blue.

You really notice when I wear blue shirts. I am the only one in my family like this. Aura on August 12, 2018: my dad is the only person in the whole family with blue eyes Ian on June 22, 2018: Also, maybe there was also something about climate/environment of European countries that caused the mutation to occur more frequently.

Somebody on May 21, 2018: My whole family have blue eyes, I feel lucky. Anon on May 13, 2018: Not all black people are African American. Asia on April 09, 2018: why did you have to use black people why couldnt you use African american Anonymous on April 03, 2018: False propoganda? And where is your proof, Aly? Aly Julmiste on March 29, 2018: To my understanding, blacks with blue eyes and blond hair were the oldest of human kind.

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There was a tribe in south africa that research has shown that they were the first original humans and they were with blonde hair and blue eye. You are making this highly wrong hypothesis that blue eyes came originated from Europeans and some other predominantly white countries. Stop spreading this false propoganda.

The truth is every single ethnic group came from the black. That has been a proven fact. At some point some of these blacks started moving to different parts of the world millions of years ago; including some of those that were in the tribe of south Africa that had the blue eyes and blonde hair.

  1. The ones with the blonde hair and blue eyes all moved to the European regions and the other blacks moved to diffrrent parts of the world.
  2. These blacks that moved from Africa after so many years, evolution started taking place.
  3. Their skin color and hair structure started to change due to weather and different climates their bodies weren’t use to.

After millions of years that became the result of all these different races. Even though the blacks with the blue eyes and blonde hair did have their skin color changed to white and changed their hair texture due to evolution, the two characteristics that did not changed were their blonde hair and blue eyes.

  1. What that means is whites with blond hair and blue eyes are descendants of that tribe in south Africa that had the blue eyes and blond hair.
  2. Every nation started off with their ancestors being of black people being their original.
  3. This has been proven time and time again by some of the greatest genealogists.

Don’t be one of those that hate to admit that blacks are the originals. And then try to convince people and alternative theory just so you can undermined that blacks are the originals. idiots on February 24, 2018: Wow. The comments here show that it’s actually INTELLIGENCE that’s rare- not blue eyes.

Eliza Fleming on January 29, 2018: Mwindo it doesnt matter if they were not fully black Mwindo on January 20, 2018: Those american actors you mentioned are not fully black, so them having blue eyes can be easily explained. Mary Love on December 11, 2017: So I’m a genetic mutation? I am African American and I have blue eyes.

You can see it when sunlight or bright lights shine in my face. I was unaware of this growing up and only found out after I became a teenager. What is the problem? Where did I get blue eyes from? My parents eyes were brown. Why are mine blue?? Any answers? Maggie on November 30, 2017: Everywhere I go I meet black people with blue eyes or blonde hair, blond lashes and eyebrows blonde skin hair and blue eyes or green eyes.

  • Black people and white people get married and or have children together and pass on these genetic traits that turn up immediately or somewhere down the line of future generations who may not know there is white blood in their DNA.
  • None that I have know ever had a disease causing blue eyes as if something must be wrong with that person or its a mutation of some sort.

Giwreh on November 14, 2017: Hello. In the article, you use the expression : “. there are quite a few black people with blue eyes.” However I wonder what quite a few means. Rather : “extreme rare” ?? I get the impression from daily life that if I assume 0,01% got them, I’m still exagerating ? 🙂 Cheers CubanFlowers on October 29, 2017: to Drummond.D sweetie.

Hi.and what makes you think. that baby needs adopting??? because he. is poor person????? that means he has no parents. and if he does have parents. they will just give to you their baby. because they are ‘poor’??????. be blessed Kevin on September 04, 2017: Some of the photos in your article look like genetic manipulation.

Someone must have changed these eyes on purpose, like mine in 1988. Susan on August 28, 2017: Here is another interesting bit of research on blue eyed ancestors. predating the Baltic Sea area, if I have it right: http://news.nationalgeographic.com/news/2014/01/14.

Edmund Custers (author) on August 25, 2017: Hey Jojoblueeyes, thank you for posting such an interesting comment. I am glad you enjoy reading this article. I must say, I enjoyed reading your comment. This is the first time I have come across this theory—that if only the father has blue eyes the child has a higher probability of having blue eyes than if only the mother has blue eyes.

Personally, I think is it highly unlikely. While there may be little to no data today, to provide an answer to this question, let us keep it open for further discussion. Cheers! Jojoblueeyes on August 25, 2017: Just wanted to start off by saying thank you for this insightful article.

It was very informative, well put together, easy to read and understand, and very interesting. I am a young Mexican American woman with European ancestry. My eyes are an auburn color, and my son’s dad’s eyes are a pale blue. My 4 year old son has greenish blue eyes but they are more blue than green. They also have specs of my eye color in them which is pretty amazing.

Most of the time they look more on the blue side but other times they appear to be more on the green side, and sometimes even look almost like a hazel. Have you ever dropped food coloring of different colors into water and watch it expand outward together, but not exactly mixing? That is how I would describe my son’s eyes.

  • Before I gave birth to my son, I always wondered what color his eyes would be because his father’s eyes are blue.
  • I was told by a few people that if the father has blue eyes, the baby had a higher chance of inheriting his eye color more so than if the mother has blue eyes.
  • I’m not exactly sure how true this is because my husband (son’s step father) has blue eyes but his son has dark brown eyes like his mother, and my brother in law also has blue eyes but his son has dark brown eyes like HIS mother.

Not exactly sure if my son has blue eyes because his father has blue eyes, or because both his father and I somehow carry the blue eye gene, or if it just happened on random. Anyways, if you are reading this, what do you think? Drummond.D on August 17, 2017: I heard what beautiful eyes on the little baby boy, no one is looking at how poor he is can I help like adopt him does any one knows who took the pick or any info [email protected] on July 08, 2017: I am Native American Indian/Caucasion.

My mom had dark brown hair and brown eyes. My dad had dark brown hair and hazel eyes. I have medium brown hair and figuring hazel eyes. My grandpas full brother had bright blue eyes, other than me and him everyone else has brown eyes even distant cousins. My eyes are grayish-green in normal light, emerald green in sunlight straight on and amber in sunlight from the side view, I am assuming that means hazel.

My 3 year olds eyes seem to be exactly the same as mine. Her daddy has dark blue eyes. If we have another kid I am wondering what color the eyes will be genetically speaking. Coming from an almost entirely brown eyes family I am surprised mine are not brown.

Cee on June 07, 2017: Hi, I’m black but I have hazel eyes and my mum and dad have dark brown eyes, I’m from Nigeria, Two of my siblings have light brown eyes too melanated woman on June 05, 2017: Blue eyes is a recessive mutation, weather it’s in European or in Africa and most likely it originated in Africa.

Why Do You Have Blue Eyes?

Sickle cell protects Africans against malaria it only becomes a problem when they move from the area that have no malaria. Some white people with brown eyes have sickle cell. The solution will be to infect sickle cell carrying people with malaria. Dunnyboy on April 30, 2017: my parents are black with brown eyes.was born with blue eyes and im told its some wardensberg syndrome which honestly speaking.I dont think it prevents me from seeing.i see just normal.no problem with my eyes Amanda Whittaker on April 28, 2017: Beautiful beautiful beautiful baby blue sapphire eyes on a beautiful brown baby boy! So so stunning and great [email protected] on March 16, 2017: I have little girl 10 month old have a nice blue eyes both parents have black eyes.

I’m from Ghana Africa Edmund Custers (author) on March 03, 2017: Sherrie, thank you for the interesting comment. There are several reports showing that sickle cell disease can affect the eye in different ways. It can lead to the accumulation of bilirubin – a pigment the causes the yellowing of the skin and the white of the eye.

Sickle cell is believed to also affect the blood vessels/blood flow in the eye (causing ‘red eye’) and I think this can be an important factor when looking at a potential relationship between eye color and sickle cell. Sherrie on March 03, 2017: In light of your discoveries with eye color how will this affect the way you look at & study sickle – cell is there a link ? Savage on January 21, 2017: The blue eye gene came from one fallen angel with blue eyes and dark skin.

It’s in the book of Enoch. Rodrigo Sebidos from Zone2 Brgy.Guadalupe, Baybay City, Leyte, Philippines on September 23, 2016: Very possible because of mutation, a sudden heritable change. For instance, the Eve gene for eye/skin color originated from a black woman, a mutation that occurred in the mitochondria thousands of years ago.

Mitochondria is a cell organelle that possessed its own DNA independent of the DNA in the Nucleus of the Cell. This genetic anomaly is transmitted only by women since they are the one that contributes the mitochondrial DNA through the egg(sexual gametes) Edmund Custers (author) on September 20, 2016: Hi Frumpleton, the inheritance of eye color is complicated and you’ve just presented a good example of how a parent with brown eyes have been kids with lighter eye colors.

See also:  What Dog Has Green Eyes?

Thanks! Hi Glenis, Cee-Jay A., thank you for stopping by and commenting. Cee-Jay Aurinko from Cape Town, South Africa on September 20, 2016: I’m a browned eyed guy. Everyone in my family has brown eyes as far as I know. Well, almost. I have a cousin that yellowish eyes. Like for real. Guy looks like a cat.

Great hubbing, Edmund Custers. Glen Rix from UK on September 19, 2016: I once knew an African Caribbean man who had blue eyes. I assumed that their history lay in the slave trade, when some white slavers would breed children with their female slaves. frumpleton on September 19, 2016: My two sisters and I all have different eye color and hair color.

Why are blue eyes becoming rarer in America?

Blue eyes are increasingly rare in America – Americas – International Herald Tribune (Published 2006)

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If the U.S. Census Bureau has it right, the 300 millionth American entered the United States kicking and screaming on Tuesday morning. The odds are that this milestone American is a boy, born to a white family in a California suburb. He will have a 1-in-4 shot of graduating from college, will probably marry, father two children, struggle with his weight, and live to see his 85th birthday.

  1. What he will probably not have – that his grandfather likely did – is a pair of blue eyes.
  2. Once a hallmark of the boy and girl next door, blue eyes have become increasingly rare among American children.
  3. Immigration patterns, intermarriage, and genetics all play a part in their steady decline.
  4. While the drop-off has been a century in the making, the plunge in the past few decades has taken place at a remarkable rate.

About half of Americans born at the turn of the 20th century had blue eyes, according to a 2002 Loyola University study in Chicago. By mid-century that number had dropped to a third. Today only about one 1 of every 6 Americans has blue eyes, said Mark Grant, the epidemiologist who conducted the study.

Grant was moved to research the subject when he noticed that blue eyes were much more prevalent among his elderly patients in the nursing home where he worked than in the general population. At first he thought blue eyes might be connected to life expectancy, so he began comparing data from early 20th- century health surveys.

Turns out it has more to do with marriage patterns. A century ago, 80 percent of people married within their ethnic group, Grant said. Blue eyes – a genetically recessive trait – were routinely passed down, especially among people of English, Irish, and Northern European ancestry.

By mid-century, a person’s level of education – and not ethnicity – became the primary factor in selecting a spouse. As intermarriage between ethnic groups became the norm, blue eyes began to disappear, replaced by brown. The influx of nonwhites into the United States, especially from Latin America and Asia, hastened the disappearance.

Between 1900 and 1950, only about 1 in 10 Americans was nonwhite. Today that ratio is 1 in 3. With the exception of an increased risk of macular degeneration (blue eyes are at greater risk), eye color is biologically indicative of almost nothing. Boys are 3 percent to 5 percent likelier to have blue eyes than girls, but beyond that it’s a non-issue – physiologically speaking.

  1. The cultural implications are another story.
  2. Preferences for fair skin and blue eyes stretch back in Europe to at least the Middle Ages, according to Hema Sundaram, author of “Face Value,” a book about the history of beauty.
  3. For women in particular, especially those of European descent, fair skin and light eyes have long been seen as indicators of fertility and beauty.

America adopted those biases early on, and Hollywood reinforced them by anointing a long line of blue-eyed blondes such as Marilyn Monroe as the nation’s sex symbols. In the 1930s, eugenicists used the disappearance of blue eyes as a rallying cry to support immigration restrictions.

  • They went so far as to map the parts of the country with the highest and lowest percentage of blue-eyed people.
  • So consumed were Americans with this ideal that in the ’70s and ’80s the fashion models who exemplified the All-American look were typically Scandinavian, said Katie Ford, CEO of Ford Models in New York, which has been in business for 60 years.

But in the past decade those standards have begun to change, and Madison Avenue has taken note. The look advertisers want today favors honey-colored skin, brown hair, and green or brown eyes. The most successful models are coming from Brazil. “Advertisers want the idealized form of the general population,” Ford said.

  • Someone with perfect features but who the everyday person can relate to.” But even as blue eyes give way to brown, lighter eyes will maintain a certain allure, said Carolyn Kaufman, who teaches evolutionary psychology at Otterbein College in Ohio.
  • When people see something pleasurable, their eyes dilate, Kaufman said.

Dilated pupils signal happiness and are, in turn, considered attractive. Since they are easier to see on lighter eyes, they have a natural appeal. : Blue eyes are increasingly rare in America – Americas – International Herald Tribune (Published 2006)

Why did humans evolve blue eyes?

Why did humans evolve blue eyes? This gradient gave rise to the ‘vitamin D hypothesis’, which is the idea that light coloured skin, hair and eyes co- evolved as humans moved into latitudes where shorter days and summers meant they got less sunlight.

What is the genetic origin of blue eyes?

Blue Eyes Originated 10,000 Years Ago in the Black Sea Region A team of researchers from Copenhagen University have located a single mutation that causes the mysterious phenomenon of blue eyes. And all blue-eyed people are genetically related to a person who lived in the Black Sea region sometime between 6 – 10,000 years ago.

The research was published in the Journal of Human Genetics. A mutation in a gene called OCA2 came into being nearly 8,000 years ago. It can be definitively traced back to an ancestor from the Black Sea. Dr. Hans Eiberg claims that before this time, every human being had brown eyes. “A genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a ‘switch,’ which literally ‘turned off’ the ability to produce brown eyes,” Eiberg said.

When blue-eyed peoples from Jordan, Denmark, and Turkey were examined, their genetic difference was traced back to the maternal lineage according to Eiberg’s team. The brown melanin pigment is still dominant. However, following the last Ice Age, Europeans developed this rare mutation that differentiated them from the rest of the human race.

Ninety-five percent of Europeans in Scandinavian countries have blue eyes. They are also found to have a greater range of hair and skin color. Comparatively, Europe has a wider variety of hair color and skin pigment than is found in any other continent in the world. These mutations are recent as Europe was colonized only a few thousand years ago, say mainstream scientists.

Through interbreeding, the brunette with blue eyes was evidenced about 25,000 years ago. Researchers attribute this to ancient interbreeding with Neanderthals. Although no Neanderthal DNA has been found in modern Homo Sapien-Sapien, mainstream science clings to this theory as fact because they haven’t come up with anything better.