Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum One Common Ancestor Behind Blue Eyes

"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. "

http://www.livescience.com/health/080131-blue-eyes.html

So according to the last sentence of the article--are blue-eyed people more fertile, as well as being extremely nice people? Surely eye colour is not linked to fertility is it?.

(I have blue eyes!!!!)

I'm not sure about the fertility aspect, but it appears to confer some selective advantage to survival. Maybe not so much in our modern, concrete canyon existence, but at some point it must have been advantageous to carry the gene. Remember that the gene for sickle cell anemia confers resistance to malaria. Perhaps blue-eyed people are somehow resistant to certain parasites.

Living as I do in a sunny country I am aware that we pale eyed/skinned people are in danger of sun caused burning and thus skin cancers for most of the year. Maybe this tendency to burning allows for greater absorption of Vitamin D -- or something.

Ellis: "Maybe this tendency to burning allows for greater absorption of Vitamin D"

Yes, the two do go hand in hand. Melanin helps prevent burning but also prevents vitamin D production:

"In addition, dark skinned people (whether natural or induced) are more susceptible to this disease [rickets] since skin pigment can block absorption of the sun's rays. Therefore, once a suntan is established, Vitamin D production through the skin no longer occurs."

http://www.innvista.com/health/nutrition/vitamins/d.htm

[quote=Mike Kremer]

Of course you have got Blue eyes Ellis!!
And you are an extremely nice person!!

Thats because we have evolved from Monkeys!!!
And Monkeys evolved from the smaller Lemur monkey.

And many Lemurs have blue and even green eyes

Ok! Are you an Evolutionist, or a Creationist?
Nows your chance to decide!!Hehehe

Well I for one didnt quite believe that our Blue eyes evolved
rather late in our evolution. As stated in Amaranths original post.

So I searched and found some Blue and Green eyed monkey types.

http://www.primates.com/lemurs/lemurblue.htm

We did not evolve from monkeys. Rather, humans and monkeys evolved from a common ancestor.

If there are extant monkeys that have blue eyes, it could be that they acquired them separately from humans.

Is this a minor case of convergent evolution conferring the same benefits (whatever they might be) to each of the species, or is it, in each case, one of those mutations that serve no useful purpose? - Except that it makes Ellis an extremely nice person

I wonder if the blue eye colour gene is disappearing, as it is supposed to be recessive. From this article it does not seem to be so. What has the eye colour of monkeys to do with this topic? We did not evolve from monkeys, but from a common ancestor as suggested by FF.

I think I'll have to delete the 'extremely'--- I am really only nice some of the time, (just like everyone else)!

Ellis ('nice some of the time'): "What has the eye colour of monkeys to do with this topic? We did not evolve from monkeys..."

I was under the misapprehension that the words 'convergent evolution' would preclude that question. I'll elucidate: I simply queried the possibility of a single genetic advantage being shared by certain blue-eyed primates.

We ARE related to monkeys. We know there are blue-eyed humans. If there are blue-eyed monkeys, it makes sense to suspect the blue-eyed trait might have originated with some common ancestor - and maybe it did. Rose's link, however, suggests that this is not the case, that in fact our blue eyes came about long after humans and monkeys diverged. The report doesn't indicate when monkeys developed blue eyes. But at this point, based on nothing else, and assuming their study is correct, it seems that our initial assumption would have been false and that the blue-eyed trait is a candidate example of convergent evolution.

Yes, quite TFF. I, for one, would be extremely interested to know why it has occurred, and if the reason is the same in each of the species - which would seem likely, but it's not necessarily the case.

It wouldn't be the same reason would it? The advantage of pale eyes and skin is that the absorption of vit. D is more efficient in areas of low sunshine (eg Northern Europe), and monkeys do/did not happen in such climates. As this adaption occurred fairly recently, this sun protection seems to confer a definite advantage in Northern Europe not needed by fur covered monkeys in sunny climates. Or is that simplistic?

There are other examples of good/ bad mutations such as sickle cell anaemia (already mentioned), and I remember reading a theory that cystic fibrosis, by thickening the secretions in the body, made it somewhat harder for TB bacteria to flourish in the crowded early cities of Northern Europe.

Apparently there are blue eyed tigers!!

Ellis: "It wouldn't be the same reason would it?"

I really don't have a clue. Wouldn't like to guess. Quite possibly there's no advantage in it at all. After all, there are plenty of people in the world with melanin in the irises but not in the skin, so they still have the ability to manufacture vitamin D. As you say, all manner of chance mutations occur, some very useful, some less so, and some detrimental. Maybe the 'blue eye' mutation occurs from time to time in many species without having a positive value.

Of, course, there may be more to it than meets the eye (oops!)

I forgot to mention our possible REAL ancestor, (Orrorin Man?) a missing link between the Apes and ourselves, that goes back even further than 'Flat-Faced Man'
Two groups of Paleoanthropologists are still working upon the group of 5 individuals found.
What is not in dispute is, that they walked on the ground over 6 million years ago!
Dont know about their eye colouring. Hehe

http://cogweb.ucla.edu/ep/Orrorin.html