system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we need to spend nearly one-third of our life sleeping? Why did evolution not bring that number down?
gpt
For starters, you have the fundamental fallacy of evolution.  It does not have direction.  HAD a random mutation occurred to eliminate sleep, it might have flourished.  

but then, night time is dangerous, and sleeping is a good way to conserve energy and avoid predators, so maybe wandering around at night would have been bad.