Why do so many organisms, like mammals, need sleep to a degree that it makes it a requirement to live like food and water, while other organisms don’t sleep at all?

Question

Sleep does a lot of things here and there, but has there been a thesis pin pointing the exact thing that absolutley requires sleep? Could it be that the brain, even the ones not as evolved as the human ones, can not go on for long without rest due to their bio-chemistry or something like that? Very primitive “brains” like insects and so on don’t require so much brain power like more complex organisms, maybe?

In: Biology

Answer 1

We don’t know. I remember the head of sleep research from a major university said that, after spending over 20 years in the field, as far as he knows the only really solid reason people need to sleep is because they get tired.