Racial differences, why are (native) Africans black and...?

Question

and native brits white/caucasian? Surely black skin is not favourable skin colour in a hot country because, black, dark colours absorb the suns heat and in a country like africa there is lots of sun and heat. whereas, white skin, white surfaces reflect heat therefore, white skin would be better in a hot country and black skin in a cold country?

Answer 1

The properties in materials and skin are not interchangeable:

Black skin is a biological adaptation. It is rich in melanin (pigmentation) which protects the skin from the sun by filtering UV rays moreso than white skin. This means that the darker you are, you have less chance of getting sunburnt.

As far as materials go, that's a physics thing; as far as I know, white reflects all other colours in the spectrum (including UV and infrared so it reflects their heat also), whereas black absorbs all the colours in the spectrum as well as the heat.

Answer 2

Because of the Einviroment we live in

Brits are used to cold weather so dont need dark skin cause they wont get sun burn

Africans get alot of Sun so if they where white

BAM sun burn

Answer 3

It's to do with melanin- that's the chemical that makes black skin dark, and makes freckles dark.

Basically, depending on the amount you have, the better suited you are to direct sun.

In North European countries, the sun isn't strong enough to burn fair skin (think Scandinavia) and so melanin isn't needed.

Melanin also stops you from properly absorbing vitamin D. In cold countries where there is little sun, a small amount of melanin helps as you can absorb Vitamin D more effectively. This is why, evolutionary wise, not everyone is black.

Black skin is more suited to extreme sun, where there is plenty of chance to absorb Vitamin D. White skin needs to absorb every trace of Vitamin D it can get from the watery and weak sun.

Also, about the black absorbing heat thing, that's recently been debated. I'm not sure if it's been declared an old wife's tale yet.

Answer 4

Have you ever been to one of these countries? spend a week in africa and your skin will start to tan and get darker.