I didn't say that we are descendants of people who stayed in the sun for 10 to 30 minutes a day. Yes clearly our ancestors spent more time outdoors but science now concluded that it wasn't necessarily a good thing. I think our ancestors didn't worry much about getting melanomas at 60 years old, considering that not many of them lived to that age, and even worse they didn't care much about the premature aging caused by the sun. a lot of things are great and beneficial in moderation but can turn toxic when abused. You talk about the fact that the sun is fundamental for the human body, yes it surely has an effect on boosting mood and the production of vitamin D, but honestly I see no benefit in overexposure. Personally I feel much better when I have healthy skin.