The most obvious evidence to me has always been that Europeans are not black. A change like the loss of melanin requires selective pressure, which in this case was likely furnished by less vitamin D as we migrated away from the equator. The pressure must have been significant since being white carries a big downside: higher vulnerability to sunburn and skin cancer. When I lived in Cali I always envied my darker skinned friends who did not have to smear goo on themselves at the beach.
I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed.
I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed.