system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are we still prone to sunlight radiation, given the sun was there our entire existence?
gpt
Evolution doesn't care if we're happy. It doesn't care if we live to a ripe old age surrounded by our great grandchildren. It doesn't care if we die of relatively painless kidney failure at 90 or agonizingly painful skin cancer at 30.

It cares about whether we reproduce.

Sunlight doesn't kill us fast enough to prevent that. Most of the time, people who get melanoma are able to have kids first, and then the genes which allowed them to get melanoma go along for the ride.

Diseases which kill too slowly just aren't selected against by evolution. It's why we still have Huntington's Disease, which eats your brain starting from age 35. It's why prostate cancer is so dang common, as most people get it when they're in their 60s. The BRCA-1 gene which causes breast cancer? Doesn't matter a bit to evolution.

Evolution isn't magic. It won't solve our problems, and is in fact incapable of solving them. That's our job.