system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Our planet is dominated by salt water, and we humans have not evolved to drink it. Why ?
gpt
Evolution is not a guided process. Evolution doesn't think 'god there is a lot of salt water, it would be great to evolve the ability to drink that'. Random mutations just happen and if those happen to pay off (or at least not actively disadvantage the individual) they get passed on. Is it possible that during our history there were some individuals who had more efficient kidneys and could filter out more salt? Sure. But as those individuals were never in an environment were that trait would've given them a serious leg up compared to others (humans, after all, had a tendency to stick to bodies of fresh water) a trait like that wouldn't have spread around the entire population.