All Blue-Eyed People Have Common Ancestor

[Mike]

http://www.sciencedaily.com/releases/2008/01/080130170343.htm

 

[redrobin]

Ridiculous

 

[BRG]

Another stupid wasteful thing that I am sure tax payers had to pay for

 

[Silver]

I thought it was interesting. If it's true it raises some questions about the blue eyed Indians that were living here when the first Europeans arrived. :shock:

 

[Mike]

http://www.youtube.com/watch?v=2peHybUNg9Y

 

[redrobin]

I thought it was interesting. If it's true it raises some questions about the blue eyed Indians that were living here when the first Europeans arrived. :shock:

I have a serious and hopefully thought provoking question, how can a genetic mutation add genetic information?

 

[Mike]

I thought it was interesting. If it's true it raises some questions about the blue eyed Indians that were living here when the first Europeans arrived. :shock:

I have a serious and hopefully thought provoking question, how can a genetic mutation add genetic information?

Polymorphism?

 

[redrobin]

I thought it was interesting. If it's true it raises some questions about the blue eyed Indians that were living here when the first Europeans arrived. :shock:

I have a serious and hopefully thought provoking question, how can a genetic mutation add genetic information?

Polymorphism?

Possibly but why would a large percentage of the worlds population now contain the mutation if that's the case? Survivability doesn't increase with blue eyes. As a matter of fact, I'd suspect that blue eyes are on the decline. I'd guess that they have been on the decrease since creation. Blue eyes were genetically available at creation and genetic information in general has been decreasing since then.

 

[Mike]

I have a serious and hopefully thought provoking question, how can a genetic mutation add genetic information?

Polymorphism?

Possibly but why would a large percentage of the worlds population now contain the mutation if that's the case? Survivability doesn't increase with blue eyes. As a matter of fact, I'd suspect that blue eyes are on the decline. I'd guess that they have been on the decrease since creation. Blue eyes were genetically available at creation and genetic information in general has been decreasing since then.

Thanks for your input, but I think I'll rely on the research as written. :wink:

The first lesson in genetics is Mendel.

The second is everything is not Mendelian.

 

[redrobin]

Polymorphism?

Possibly but why would a large percentage of the worlds population now contain the mutation if that's the case? .

Thanks for your input, but I think I'll rely on the research as written. :wink:
.

I'd be interested in seeing the research. Please present the scientific answer as to why so many blue eyes from a mutation?

 

[Mike]

Possibly but why would a large percentage of the worlds population now contain the mutation if that's the case? .

Thanks for your input, but I think I'll rely on the research as written. :wink:
.

I'd be interested in seeing the research. Please present the scientific answer as to why so many blue eyes from a mutation?

Same reason Asians have thicker hair shafts, smaller breasts, more fat cover on the eyelids, an increase in sweat glands, etc. etc. ?

http://www.nytimes.com/2013/02/15/science/studying-recent-human-evolution-at-the-genetic-level.html?_r=0

Abstract from the peer reviewed research:

http://www.cell.com/abstract/S0092-8674%2813%2900067-6

You'll have to pay for the whole study. :lol:

 

[Denny]

I thought we all traced back to Adam and Eve

 

[Mike]

I thought we all traced back to Adam and Eve

Looks as though the blue eyed mutation happened way before Adam & Eve. :lol: :lol:

 

[Whitewing]

It's been a LONG time since I studied genetics but I do recall that blue eyes result from recessive genes....that's to say, both parents must have the recessive gene in order for a child to be born with blue eyes.

Don't know how it all relates to DNA markers and the such discussed in the article but I'm having a hard time wrapping my brain around the comment that blue eyes can be traced back to a single individual.

 

[Mike]

The laws of genetics state that eye color is inherited as follows:

1-If both parents have blue eyes, the children will have blue eyes.

2-The brown eye form of the eye color gene (or allele) is dominant, whereas the blue eye allele is recessive.

3-If both parents have brown eyes yet carry the allele for blue eyes, a quarter of the children will have blue eyes, and three quarters will have brown eyes.

There are two layers to the iris, the anterior and the external, or front and back layers. To produce blue eyes, there is no pigment found in the front layer. The brown pigment melanin is deposited in the back layer only. It appears blue because of reflection and diffraction of light. In green eyes, a small amount of melanin is deposited in the front layer of the iris along with the melanin found in the back layer. The additional pigment to the amount needed for blue eyes, causes the eye to appear green. To produce gray eyes, the dark pigment is distributed in the front layer of the iris and over the blue background it appears gray. In brown eyes there is so much pigment in the front layer, that the blue behind is completely covered up. Some people have so much pigment in the front layer that their eyes appear very dark brown or black. Hazel, blue-green, gray-blue eye colors are produced by different amounts of pigmentation and the pattern in which the pigment is placed. Albino eyes are have no pigment at all in either layer of the iris. The iris appears pink or red because of the reflection of blood vessels in the back of the eye. The pattern in which the pigment is deposited is also determined by genetics. The pigment may be deposited in rings, clouds, radial stripes, or spread over the entire iris.

 

[redrobin]

Thanks for your input, but I think I'll rely on the research as written. :wink:
.

I'd be interested in seeing the research. Please present the scientific answer as to why so many blue eyes from a mutation?

Same reason Asians have thicker hair shafts, smaller breasts, more fat cover on the eyelids, an increase in sweat glands, etc. etc. ?

http://www.nytimes.com/2013/02/15/science/studying-recent-human-evolution-at-the-genetic-level.html?_r=0

Abstract from the peer reviewed research:

http://www.cell.com/abstract/S0092-8674%2813%2900067-6

You'll have to pay for the whole study. :lol:

When an asian has a child with a non asian, the offspring still has thicker hair, etc. When a blue eyed person has a child with a brown eyed person (remember that was all there was in your scenario) you get brown eyes with a blue eye recessive gene. Seems to me that it'd be hard to start blue eyes from that deal. I'm not a geneticist though and don't understand all I should. Please explain more.

 

[Mike]

Maybe those blue eyed people were "Linebreeding"? :lol:

 

[redrobin]

Maybe those blue eyed people were "Linebreeding"? :lol:

With who?

 

[Mike]

People with blue eyes have a single, common ancestor, according to new research.

A team of scientists has tracked down a genetic mutation that leads to blue eyes. The mutation occurred between 6,000 and 10,000 years ago. Before then, there were no blue eyes.

"Originally, we all had brown eyes," said Hans Eiberg from the Department of Cellular and Molecular Medicine at the University of Copenhagen.


The mutation affected the so-called OCA2 gene, which is involved in the production of melanin, the pigment that gives color to our hair, eyes and skin.

"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.

The genetic switch is located in the gene adjacent to OCA2 and rather than completely turning off the gene, the switch limits its action, which reduces the production of melanin in the iris. In effect, the turned-down switch diluted brown eyes to blue.

If the OCA2 gene had been completely shut down, our hair, eyes and skin would be melanin-less, a condition known as albinism.

"It's exactly what I sort of expected to see from what we know about selection around this area," said John Hawks of the University of Wisconsin-Madison, referring to the study results regarding the OCA2 gene. Hawks was not involved in the current study.

Baby blues

Eiberg and his team examined DNA from mitochondria, the cells' energy-making structures, of blue-eyed individuals in countries including Jordan, Denmark and Turkey. This genetic material comes from females, so it can trace maternal lineages.

They specifically looked at sequences of DNA on the OCA2 gene and the genetic mutation associated with turning down melanin production.

Over the course of several generations, segments of ancestral DNA get shuffled so that individuals have varying sequences. Some of these segments, however, that haven't been reshuffled are called haplotypes. If a group of individuals shares long haplotypes, that means the sequence arose relatively recently in our human ancestors. The DNA sequence didn't have enough time to get mixed up.

"What they were able to show is that the people who have blue eyes in Denmark, as far as Jordan, these people all have this same haplotype, they all have exactly the same gene changes that are all linked to this one mutation that makes eyes blue," Hawks said in a telephone interview.

Melanin switch

The mutation is what regulates the OCA2 switch for melanin production. And depending on the amount of melanin in the iris, a person can end up with eye color ranging from brown to green. Brown-eyed individuals have considerable individual variation in the area of their DNA that controls melanin production. But they found that blue-eyed individuals only have a small degree of variation in the amount of melanin in their eyes.

"Out of 800 persons we have only found one person which didn't fit — but his eye color was blue with a single brown spot," Eiberg told LiveScience, referring to the finding that blue-eyed individuals all had the same sequence of DNA linked with melanin production.

"From this we can conclude that all blue-eyed individuals are linked to the same ancestor," Eiberg said. "They have all inherited the same switch at exactly the same spot in their DNA." Eiberg and his colleagues detailed their study in the Jan. 3 online edition of the journal Human Genetics.

That genetic switch somehow spread throughout Europe and now other parts of the world.

"The question really is, 'Why did we go from having nobody on Earth with blue eyes 10,000 years ago to having 20 or 40 percent of Europeans having blue eyes now?" Hawks said. "This gene does something good for people. It makes them have more kids."

 

[Whitewing]

When an asian has a child with a non asian, the offspring still has thicker hair, etc. When a blue eyed person has a child with a brown eyed person (remember that was all there was in your scenario) you get brown eyes with a blue eye recessive gene.

Your highlighted statement isn't totally accurate..

In its simplist form, there are two genes for eye color:

B = Brown eye
b = Blue eye

Here are your possible combinations:

Person A: BB Brown eyes
Person B: Bb Brown eyes with recessive gene for blue eyes
Person C: bb Blue eyes

The example Mike quoted above is matching two Persons B.

Match Person A with Person C and every child will have brown eyes, though each will carry the recessive gene for blue eyes, Bb

Match Person A with Person B, all will have brown eyes; one quarter with the recessive gene for blue eyes

Match Person B with Person C, 50% brown eyes, 50% blue eyes (I think, but it's too late for me to say definitely)

Match two Persons C, all will have blue eyes.