Why are Africans black and Scandinavians very white? The climate situation would dictate the opposite?

The skin color is for protection from the damage of UV rays. Consider that all darker complexions are found in primarily tropical/Ecuatorial line countries. The more exposure to harsher sunlight the darker the complexion. In contrast, the Scandinavian would not require the same protection as they would be in higher latitudes.

I'd agree that it is an anomoly. You'd think it would be better to have white skin in Africa as it would reflect the sun. The black melatonin must be so imprtant as UV protection, it must outweigh the disadvantage.

Clarification on the scandinavian point. White skin will keep you warmer up North as it doesn't radiate as much heat as black skin. Yes, black skin would absorb more of the suns heat, but in scandinavia there isn't much sun and it is better to have a skin colour that radiates the minimum rather than absorbs the maximum

The pigment responsible for skin color is to protect against UV. Something people who live in sunny or equatorial areas are exposed to more of. Scandinavians live in higher latitudes and in a more cloudy environment.

Diet plays a role in skin color. The subsistence farming diet of neolithic Europeans is responsible for our pastiness. Hunter gatherer peoples who live at high latitudes are typically darker. It's pretty sunny in the high arctic, they don't have to contend with moisture coming up off the Atlantic making it cloudy like it is in Scandinavia.

Not enough vitamin-d in grains to support healthy bone growth. The more meaty diets of the hunters provides enough vitamin-d to preventing the need to lighten up.

Without direct vitamin-d the body has to manufacture it from precursor nutrients, to do so requires the less dangerous wavelengths of UV which are blocked by skin pigments.

Dark skin + cloudy climate + vitamin-d deficiency = rickets

Rickets stunts bone growth. You might survive a mild case growing up, but you'd be a bit short. If you were a woman it'd mean a smaller pelvic opening and a much greater risk of death during childbirth. Natural selection in action.

It has nothing to do with heat. Dark skin does not absorb heat and white skin does not reflect heat. Melanin protects us from UV light, dark skinned people produce more of it (and closer to the surface) than lighter skinned people... in countries where there is a lot of clouds people have very light skin... a sun tan is your body's response to high levels of UV light.

The more u r exposed to sun, the more ur skin produces melanin(I hop its correct) & d more melanin is produced, we get better protection from Sun(i.e. it helps in keeping off uv rays & many oder things).Hence African people have dark color skin(they hav more melanin) while Scandinavians do not(as they receive little sunlight).

www.smarttan.com

Tanning beds were developed in Northern Europe to see how sunlight affects MOOD, not to tan our skin. As a plus, the study gave us much information on the body's natural ability to produce melanin.

Kathya is right. People also get vitamin D from sunlight. The less sunlight available, the lighter the skin must be to get the proper amount.