Quote:
Originally Posted by Undertoad
White people, who evolved to northern climates over tens of thousands of years, do not "return" to black in a few generations if they decide to live in Africa. As animals, we too have bred; we too have changed; everything is what it is now, and that's just fine.
|
According to Nina Jablonski, an anthropologist I heard lecture about skin, pigmentation will adjust to the climate, but it takes a number of generations. The need for the species to survive drives the change.
An example she gave was Indians who have emigrated to England. Especially the female Muslim Indians who keep themselves covered. They do not get enough Vitamin D and other nutrients from the sun and frequently develop Rickets.
They can take supplements, but there are other things that go on when the sun hits the skin. Eventually, over many generations, the pigmentation of those Indian will change to allow for the greatest useage of the sun on the skin.
She said that with so many people in the U.S. conditioned to wear sunscreen and sunblock, they are finding more and more people with vitamin deficiencies.
Every human needs approx. 10 min of direct sunlight per day to remain healthy. Those with dark skin need more because the darker the pigmentation, the less of the good sun that gets through.