If humanity originated in Africa, why do white people ...?

Question

have a differenst skin, eye and hair color than the rest of the "races" in the world? If your answer is evolution, why the need to develop such characteristics? I'm not trying to be racist or nothing. I'm just curious

Answer 1

Because whites have evolved  , blacks haven't.

Answer 2

Adam and Eve had all the genes

Answer 3

We humans did start out in Africa, and we were all black.

The out of Africa migration was done during the first half of the Pleistrocence period. It was a time of ice ages, when sea levels dropped significantly and there was increased rainfall in many regions. At the same time Homo erectus was making stone tools and was able to use fire. The question of his being able to create fire has not yet been answered. Given the favorable climate and the increased skills to control his environment, Homo erectus spread out of Africa.

As for skin color and the related "racial" traits:

"In their analysis of human evolutionary history, Jablonski and Chaplin concluded that modern humans most likely evolved in the tropics, where they were exposed to high UV levels. But as they moved into regions away from the equator, where UV levels are lower, humans became fairer so as to allow enough UV radiation to penetrate their skin and produce vitamin D, the "sunshine vitamin," also obtained from eating fish and marine mammals. Vitamin D is essential for maintaining healthy blood levels of calcium and phosphorous, and thus promoting bone growth.

Skin color, according to Jablonski and Chaplin, basically becomes a balancing act between the evolutionary demands of photo-protection and the need to create vitamin D in the skin.

One of the important implications of Jablonski and Chaplin's work is that it underlines the concept of race as purely a social construct, with no scientific grounds. DNA research has shown that genetically all humans, regardless of skin color and other surface distinctions, are basically the same. In an April 2001 article titled, "The Genetic Archaeology of Race," published in the Atlantic Monthly, Steve Olson writes "the genetic variants affecting skin color and facial features are essentially meaningless —they probably involve a few hundred of the billions of nucleotides in a person's DNA. Yet societies have built elaborate systems of privilege and control on these insignificant genetic differences."

http://ngm.nationalgeographic.com/ngm/02...

"Before the mass global migrations of people during the last 500 years, dark skin color was mostly concentrated in the southern hemisphere near the equator and light color progressively increased further away, as illustrated in the map below. In fact, the majority of dark pigmented people lived within 20° of the equator. Most of the lighter pigmented people lived in the northern hemisphere north of 20° latitude."

http://anthro.palomar.edu/adapt/adapt_4....

Answer 4

The peole migrated to other parts of the world where different climates altered skin tones and body types.

Answer 5

Shooo your science teacher hasn't told you yet about Vitamin D deficiencies and why people living in northern climates need more?

Hint the more clothes you wear the less skin exposed so you need less pigment to get the UV through?

Most races have varying skin tones.

Why do you think northern Asians  tend to be paler than Khmer or Laotians or Malays?

Answer 6

No one knows why Europeans have so many hair and eye colours. It's a point of debate in a lot of anthropology arguments.

Most mutations to eye and hair colour also lighten skin (have you ever seen a ginger haired kid with dark skin?) so they are believed to be part of the way Europeans synthesized vitamin D. Although there's no good reason why the east Asians should be so dark haired and eyed if you use that argument logically.

Some of the mutations for hair colour have approximate dates to 30k and 80k, so a little Neanderthal ancestry in humans is possible. Some one worked out that it should have taken Europeans about 800k years to develop that number of hair/eye/skin mutations, which is roughly how long Neanderthals roamed Northern Europe.

http://mathildasanthropologyblog.wordpre...

http://mathildasanthropologyblog.wordpre...

Answer 7

They traced everyones DNA to a genetic marker of a tribe in Africa. Other races evolved after this marker. If you look at the people the possess many of the facial features you would see through out the world today.

Answer 8

when traveling up north body needed to adjust to changes....

Answer 9

populations of migrating people who settled in colder climates that were more cloudy for a greater number of days out of the year provided less vitamin D for the humans inhabiting these lands compared to those living in sunny Africa.  Melanin, the pigment in skin and in eyes blocks solar radiation and hence limits the amount of vitamin D absorbed by the skin.  In colder/cloudier climates, people adapted lighter skin with less pigment in order to maximize the amount of vitamin D created by what little sunlight they got.  Blue eyes and light hair are just by-products of having less overall melanin in the skin.

Why is vitamin D important to humans?  A major role of vitamin D is that it helps us absorb calcium in the intestines.