The health benefits of sunlight may outweigh the risk of skin cancer

It’s tempting to see things like this and think “well of course it does, because that’s how we evolved”. But I think that might just be post-rationalization? At the very least, I think the argument _doesn’t_ hold for periodic famine, extreme temperatures, most disease, etc even though we also evolved with those things. Is there any guiding principle that separates the things-we-evolved-with-that-are-good vs the -that-are-bad? Or is it really just a case-by-case examination?

Yeah, I've always found it a very weird and weak argument. There are plenty of things we've evolved with that would be considered pretty bad for us now. For example, we evolved as a polygamous species (like virtually all mammals), meaning harams, lots of sexless males and fighting etc.

Also important to remember evolution operates at a population level, not individual. We are descended from females that were able to survive at least pregnancy and carry the second to term, but it doesn't matter if they die in the second pregnancy. We're descended from males that were able to mate with said females, but they could have died very shortly after mating. So if you follow "what we evolved with" then that's all you're likely to get.

Where do you get the idea that we evolved as a polygamous species? The few remaining hunter-gatherer societies don't work like that. I think that kind of polygamy came with agriculture.