Asian Evolution?

Question

I was just wondering…

Why to people of Asian decent have slit eyes? I know due to the geography of Asia, these people were cut off from the rest of the world for thousands of years, and they evolved this way. Yet, what is the evolutionary advantage of slit eyes?

Answer 1

You look cooler

Answer 2

cuz therr frikin aliens man

Answer 3

Central Asia, from Mongolia to the Tibetan Plateau, is known for having high winds and dust storms. Nomadic people traveling through these regions for 10-20,000 years, naturally would have developed an adaptation to combat these conditions...

Squinting to protect from sun and wind, eventually resulted in today's modern appearance...

Answer 4

Maybe they have slit eyes that are rice shaped so they can look at each other and not feel as hungry during the long winters without rice.  Or maybe they liked to put rice in their eyes as a ritual or something praising their gods for a good rice season! That's what I would do.

Answer 5

The Ry Guy was right except that he didn't seem to realize that the reason it is found in Native Americans is that they are descended from the same people.  The oriental race developed in isolation in Tibet based on language studies.  They eyes have an extra fold of fat to provide extra warmth to the eye and aid in excess ultraviolet.  Tibet is very high in elevation and ultraviolet is a big problem there.  That is why they have black hair, a feature normally adapted for tropical sun and features evolved for cold.

Answer 6

One thing you might find of interest is that the older a population is the more diverse it is.

African characteristics are wildly diverse from the 4ft tall pigmy to the often 7ft tall Swahili. Caucasoid characteristics, though largely superficial, span from the pale skin, eyes and hair of the northern Europeans to the near black skin of southern India.(yes, they are the same race).

Not to put to fine a point on it but Asians do largely have a lot of similar traits.

This implies that Asians as a race are a newer, relatively speaking, branch of modern humans.

It may not have an evolutionary explanation. It could be a genetic trait that has yet to prove itself useful or not. If the mutation is not harmful then there is no environmental pressure to neutralize it. If it were wholly beneficial then we would probably all have it.

Answer 7

"Slit eyes" as you call them, are the result of the epicanthal fold, a structure that many of us don't share with our fellow Asian humans. This fold of skin, which sits at the bottom of the eyelid, is thought to protect the eyes from both extreme cold and light, and possibly dust.

Although we often think of Asian people as having this feature, it occurs widely around the world. Native Americans and Africans can have it. Disorders like fetal alcohol syndrome and Down's Syndrome can cause the fold to appear in people who would not normally have one.

There is also a fold of skin that can occur on the upper eyelid, which is separate from the epicanthal fold, and this can make the eyes appear even more slitted.

jim z: I realize Native Americans are descended from Asian-originating populations. A more accurate way to put it would be that Native Americans and today's Asians are more closely related by a common ancestor than they are to the rest of us. Then again, Africans have the eye fold too. Are they descended from Asians?

Answer 8

Eskimos and/or Inuits also have almond-shaped eyes.

People say that the squinting to keep the sun out of your eyes can become permanent and your eyes can stay squinted for the rest of your life.

Maybe it could carry on through genetics if two people with permanently squinted eyes had children.

It was an aquired trait that carried on through genetics after generation after generation had children.

Don't rely on all my information.

It's a theory.