IIRC, it takes around 100 generations to see a significant shift in skin pigmentation due to evolution. For humans, that would work out to about 1700 years for people that were moved from the Nordic regions to sub-Saharan Africa to develop dark skins (assuming that there were no other factors in play).
Evolution can take what seems like a really long time.
IIRC, it takes around 100 generations to see a significant shift in skin pigmentation due to evolution. For humans, that would work out to about 1700 years for people that were moved from the Nordic regions to sub-Saharan Africa to develop dark skins (assuming that there were no other factors in play).
Evolution can take what seems like a really long time.