why do black people have dark skin? why are the eyes of east asians different from the rest of us?

Question

how did all this diversity arise in only 100-50K years?

Answer 1

The environmental pressures on early humans were much much higher, with the naturally higher mortality for those who couldn't cut the mustard, genetically.
Put another way, when there are no clothes or sunshades or SPF30 sunblock, your body's response to intense sunlight, or extreme cold, or snow glare, is much MUCH more important.
Evolution takes place much faster when the odds of death are higher. The seemingly minor differences in one individual may turn out to provide overwhelmingly greater chances for survival until reproduction (after which, evolution is pretty much done with that individual, sorry AARP).
Thus, 65,000 years (roughly 5,000 generations) would be plenty of time for the development of such comparatively minor variations. After all, all human "races" are capable of producing fertile offspring - a clear sign that the apparent "diversity" is no more than the equivalent of variations in the fur color in lemmings.

Answer 2

You have taken a racially centrist position by asking why someone else is different. You are different. There is no race by which all others are measured against as a standard.
Dark skin is a natural protection from intense ultra violet
sunlight. Light skin absorbs vitamin D better in latitudes where
sunlight is dimmer.
Asians may just as well ask why Caucasian eyes are round,
unlike the the rest of us Asians. There does not seem to be
an evolutionary advantage to various eye shape. So it may only be due to random genetic drift .
The diversity arose in only the last 50k - 100k years because
human population was reduced close to the point of
extinction about that much time in the past. And it was reduced down to a small pocket of the same kind of people in the same
small area. This was determined by analyzing mitochondrial DNA
from a large and diverse sampling of the human population.

Answer 3

A better question would be why do some people have light skin. The most recent scientific evidence indicates that all humanity originated in Africa. It is most likely that the first people had darker skin (as displayed by the indigenous people of Africa, today). As some of these original peoples migrated and settled in areas of Asia and Europe, the selective pressure for eumelanin production decreased in climates where radiation from the sun was less intense. Thus variations in genes involved in melanin production began to appear in the population, resulting in lighter hair and skin in humans residing at northern latitudes. Studies have been carried out to determine whether these changes were due to genetic drift or positive selection, perhaps driven by requirement for vitamin D. In either case, Humans once all had darker skin. Our skin turned lighter over perhaps a 35,000 year period.

Answer 4

Black people have dark skin because they have more melanin, which is the pigment that colours skin.

It is possibly a product of evolution as they originated in Africa, having darker skin helps protect them from the sun and getting burned constantly. I imagine the eyes of east asians is the same a by product of evolution.

Answer 5

for things to be simple and to not sound so scientific . . .

if you look at it, the principle of adaption applies. black people usually come from africa, where the sun burns like hell. therefore, they need protection from this sun - that's why they end up with thicker and "melanin-filled" skin. It's not so hot in Asia, not so cold either - just right - so the skin is from medium-tone to pale. I don't think a black man stems originally from antartica / alaska . . . correct me if i'm wrong though.

Ancestral genes may also play a key role. Color of the skin and eyes may also result from this cause. Although, genetic mutations and "crossing-overs" may occur to bring about "new variations" of colors.

God is amazing, eh?

^_^

Answer 6

Black people =

The melanin react with sunlight and turn our skin into darker to protect our skin from further damage by the sunlight.

Eyes different =

Because we have different genetic codes that control our eyes colour.

Answer 7

Blacks were adapted to the sun in Africa. Nevertheless it is rather peculiar. When I walk in the sun I choose a white shirt. It reflects lot of the radiation and I am not overheated.
A black shirt however absorbs the sunrays strongly and heats me much more compared with a white shirt. You see peculiarity?!

Answer 8

Thats where GOD come in. Only GOD can answer your question. I think no scientists can answer you accurately too.The best they can tell you is in the genes,but why was black people black from the 1st man of that race, only GOD can tell you the answer.

Answer 9

we stem from 4 origional tribes of early man ..the a/b blood type is asian decent..2 tribes were asian

Answer 10

they are black because they have more melaline to protect their skin from the hot sunshine.