Seriously, a bad sunburn could limit our ability to survive in the wild. I’ve had a few so bad I could barely move and I had a super high fever. Desn’t that happen to animals? How do they manage?
In: 31
People are leaving out ricketts.
Humans evolved to spend some time in the Sun, because we need that to make Vitamin D. So if we had a mechanism that completely blocked sunlight, our bones would bend and we’d have a hard time in life.
Humans in very sunny parts of Africa had skin dark enough to block most of the damaging ultraviolet radiation from the Sun but still let a little through so they would have vitamin D.
When humans moved to parts of the planet that got less direct sunlight, they started suffering from inadequate vitamin D (known as “ricketts” in children). Evolution selected for people with lighter skin, but still as dark as possible to reduce sunburns and skin cancer.
The less direct sunlight we got, the lighter our skin had to get to let us make vitamin D. But it means people who have light skin are now incredibly vulnerable to sunburns and skin cancer if they spend a lot of time in brighter sunlight than they evolved for.
So humans *are* adapted to reduce sunburns, that’s what melanin is for. But by now many of us are descended from migrants who had to weaken those defenses to survive in less brightly lit climates.
Latest Answers