Researchers agree that our early australopithecine ancestors in
Africa probably had light skin beneath hairy pelts. “If you shave a
chimpanzee, its skin is light,” says evolutionary geneticist Sarah
Tishkoff of the University of Pennsylvania, the lead author of the new
study. “If you have body hair, you don’t need dark skin to protect you
from ultraviolet [UV] radiation.”
Until recently, researchers assumed that after human ancestors shed most body hair, sometime before 2 million years ago, they quickly evolved dark skin for protection from skin cancer and other harmful effects of UV radiation. Then, when humans migrated out of Africa and headed to the far north, they evolved lighter skin as an adaptation to limited sunlight. (Pale skin synthesizes more vitamin D when light is scarce.)
READ MORE:
http://www.sciencemag.org/news/2017/10/new-gene-variants-reveal-evolution-human-skin-color
by Ann Gibbons
Until recently, researchers assumed that after human ancestors shed most body hair, sometime before 2 million years ago, they quickly evolved dark skin for protection from skin cancer and other harmful effects of UV radiation. Then, when humans migrated out of Africa and headed to the far north, they evolved lighter skin as an adaptation to limited sunlight. (Pale skin synthesizes more vitamin D when light is scarce.)
READ MORE:
http://www.sciencemag.org/news/2017/10/new-gene-variants-reveal-evolution-human-skin-color
by Ann Gibbons
கருத்துகள் இல்லை:
கருத்துரையிடுக