system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we need sunscreen when our ancestors didn't? Did all our ancestors die of skin cancer?
gpt
Ancestors that lived in Africa had lots of sun, and didn't need sunscreen because of high melanin levels.  Ancestors who lived at higher latitudes (we're talking about youall in Sweden) had clothes to protect them from the sun and lighter skin color.

Ancestors that die of skin cancer after they've had children don't matter, from an evolution point of view.