It's notable that almost every animal sleeps in some way, even organisms that are away from sunlight (ie. creatures that live underground).
If you sleep 30% of the time, that's 30% of the time you aren't eating, mating, etc. Also, during sleep you are more vulnerable to predators. One would expect evolution to get rid of sleep in creatures who don't rely on sunlight cycles.
So, there must be some really good evolutionary reason for sleep.
If you sleep 30% of the time, that's 30% of the time you aren't eating, mating, etc. Also, during sleep you are more vulnerable to predators. One would expect evolution to get rid of sleep in creatures who don't rely on sunlight cycles.
So, there must be some really good evolutionary reason for sleep.