Without metallic and electrical technologies, how can humans with blonde hair, blue eyes and light adapt to the tropical environments?
- Gray BoldLv 71 month ago
Some researchers suggest that human populations over the past 50,000 years have changed from dark-skinned to light-skinned and vice versa as they migrated to different UV zones, and that such major changes in pigmentation may have happened in as little as 100 generations (≈2,500 years) through selective sweeps.
- Anonymous1 month ago
They evolved in the Caucasus region, where the climate is not tropical. Blue eyed folks do have a slightly higher incidence o eye cancer, and light skinned folks are more susceptible to skin cancer. They wear clothes and that reduces the chance of skin cancer. Glass blocks UV light, so wearing sunglasses make of glass will reduce the risk of eye cancer. Blonde hair makes no difference, and there are in fact some dark skinned people (e.g. in the Solomon Islands) that have blonde hair, ostensibly because it is not maladative and so it is not eliminated by natural selection.