Study Links Genetic Mutation of Blue Eyes to a Common Ancestor

blue eyes genetic mutation

Study Links Genetic Mutation of Blue Eyes to a Common Ancestor

Eye colors have evolved over time and are passed through ancestry. 

And interestingly, if you have blue eyes, you’re related to a lot of people and can probably identify your ancestors just by looking at them. 

Weird right!

But we are not saying this without any proof.

According to recent research, people with blue eyes have single, common ancestors. 

Key Highlights Of The Study:

  • Eye color genetic mutation that took place 6,000-10,000 years ago is the result of blue eye color.
  • Blue-eyed people share common ancestors.
  • Blue eyes genetic mutation from brown are neither negative nor positive.

Technically all eyes are of the same color. And that is because of the pigmentation, melanin, which is naturally brown and is responsible for eye color. 

And as said by the professor, Hans Eiberg, “Originally, we all had brown eyes,”

High levels of melanin make the eyes look brown whereas a low level of the same melanin pigments make the eyes appear blue. 

Now, we have a new study that offers more scoop on blue eyes genetic mutation.

 

One Common Ancestor Behind All Blue-Eyed People 

Here’s the full detail of the study related to blue eyes genetic mutation in humans. 

#1. Basis Of The Study

Have you ever thought about what makes blue eyes rarer than brown eyes?

Well, science is your genie here; it has all the answers!

A study by the University Of Copenhagen has found that people with blue eyes have single, common ancestors.

Around 6,000-10,000 years ago, a baby was born with a genetic mutation. And that DNA glitch was blue eyes. 

This blue eye genetic mutation resulted in the creation of a switch and completely turned off the ability to produce brown eyes. 

#2. Method Of The Study 

A team from the University of Copenhagen along with Professor Eiberg tracked down the blue-eyed people from diverse countries, such as Turkey, Jordan, and Denmark and compared their eye color, and examined the mitochondrial DNA. 

Moreover, by linkage analysis, Eiberg’s team was able to fine map the blue eye color. 

#3. Results Of The Study

It was discovered in the study that:

  1. A genetic mutation affecting the OCA2 gene in chromosomes caused a switch and resulted in putting off the ability to produce blue eyes.
  2. The switch in the gene adjacent to OCA2 doesn’t entirely switch off the gene but rather limits itself. 
  3. To explain, the OCA2 gene code for the so-called P protein which is responsible for producing melanin pigments reduces its production of melanin in the iris only – diluting brown eyes to blue.
  4. Blue-eyed individuals showed only a small amount of variation in the melanin in their eyes. 
  5. All the examined blue-eyed people inherited the same switch and exactly at the same point in their DNA.

So, finally, it was concluded that all people with blue eyes share common ancestors.

#4. Key Inferences From The Study

Further analysis of blue eyes genetic mutation depicts the following key inferences from the results:

  • Blue eyes mutation is neither positive nor negative mutation.
  • It is just like other mutations, such as freckles, beauty spots, baldness, or hair color.
  • It has no effect on human survival. That is to say, this eye color mutation neither increases nor decreases the chances of human survival. 

But this blue eye genetic mutation origin ended up creating something absolutely beautiful and alluring. 

The natural constant shuffle created a genetic cocktail of human chromosomes that left us with one of the most beautiful eye colors. 

Furthermore, yes, it’s true that eye color is the result of the number of melanin pigments in the iris. 

However, it is also a fact that genetic traits determine the amount of such pigmentation and are also inherited. 

Let’s dig a little deeper to gather more information.

 

Link Between Genetics And Eye Color

Is eye color genetic?

Normally every single cell in the human body contains 23 pairs of chromosomes. 

Chromosome 15 contains 600-700 genes that are responsible for producing proteins that have a significant role to play in eye color, namely, OCA2 and HERC2.

While OCA2 is responsible for producing melanin, HERC2 controls the OCA2 gene by turning its protein production on and off. 

Adding to it, even a slight genetic variation in the HERC2 gene can turn off or on the protein production and result in varied eye colors. 

So yes, eye colors are genetic to an extent. 

And since the genes go far back, it is obvious that eye colors are as well inherited. 

Interestingly, globally, less than 9% of people have blue eyes. 

But what is it about blue eyes that attracts us the most?

The uniqueness, the past connection, the hues; well, it is all that makes us fall for those baby blues.

And here we go…!

Ok now let’s come out of the trance of those sparkling sea blue eyes and move further. 

Moving on, I’m sure this study must have triggered the inquisitive person in you. 

So, here are some of the interesting blue eyes facts that will surely make your jaw drop.

 

Hypnotic Blue Eyes Facts

Blue eyes are more than just a pretty pair of eyes!

Here are some of the interesting facts about blue eyes that will blow your mind.

#1. Blue Eyes Aren’t Literally Blue

Yes, you read that right.

Blue eyes aren’t actually blue. 

The color of the eyes is actually the result of the presence of melanin which, in reality, is brown in color. 

Lack of melanin in the iris gives the eyes its blue color.

#2. Born With Blue Eyes Doesn’t Mean Blue Eyes For Life

Interestingly, if you are born with blue eyes, it doesn’t necessarily mean you’ll have blue eyes for life. 

Human eyes have less melanin pigment at birth. 

This is the reason why many children born with blue eyes witness changes in their eye color as they reach early childhood.

#3. Blue Eyes Comes With Some Risks

The presence of melanin protects the eyes from getting damaged by UV radiation and high-energy blue lights from the sun. 

Therefore, because blue eyes have comparatively less melanin, the chances of damage are more.

Some of the risks that come with blue eyes are:

  • High risk of melanoma
  • Macular degeneration

#4. Only 8% Of The Worldwide Population Has Blue Eyes

If you have blue eyes, you are among the 8% of the population who have blue eyes. 

It is a rare eye color and is most common in nationalities near northern Europe.

#5. Blue-Eyed People Have High Risk Of Alcoholism

According to a study published in the American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics, people with blue eyes have a higher risk of alcoholism. 

According to this study, European Americans with blue eyes have an 83% chance of becoming alcohol dependent as compared to those with darker eyes. 

#6. Child’s Eye Color Is Unpredictable

Blue-eyed couples don’t need to have blue-eyed children only. 

The eye’s color gets affected by 16 genes. Therefore, the children of blue-eyed people don’t need to also have blue eyes. 

Two brown-eyed people can be blessed with a blue-eyed child and vice versa.

So, basically, it’s all the result of the genetic wheel of fortune that leaves you with those blue eyes.

Wow!

Blue eyes are genuinely special in a way no one can explain. 

 

Winding Up

So, according to this study, blue eyes are not actually blue but technically less brown and are the result of genetic mutation that took place long back. 

These blue eyes genetic mutations caused the brown eyes to dissolve and form a blue shade. 

Adding to it, when further analyzed, the study depicted that people with blue eyes showed the same DNA blip at the exact same spot. 

Hence, the study summarized that blue-eyed people shared common ancestors. 

If in any way you find this blog relatable, don’t forget to share your views in the comments section below. Or share the interesting facts with your blue-eyed friends. 

 

Source Study: https://news.ku.dk/all_news/2008/blue-eyes/

Journal Reference: Blue eye color in humans may be caused by a perfectly associated founder mutation.

 

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Levin Scholten
levin@horizonclinics.org

Levin Scholten is a research fellow examining the role of oxidative stress and lifestyle changes on protein and amino acid metabolism. Drawing on his analytical awareness and investigative skills, Levin contributes to diet and supplement guides by deducing present scientific data. Read More... About Me

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