I think you overestimate the disadvantages of sleep. It's very species dependent, for some it might be a disadvantage because you're more vulnerable to predators, for others it's an advantage because you spend less energy. If you're safe you really only need enough wake time to eat and reproduce.

▲

smallmancontrov an hour ago | parent [-]

If you're safe.

▲

redox99 an hour ago | parent [-]

You definitely see a bit of this in other primates. They sleep on trees (much safer) and for a lot more hours than humans.

▲

smallmancontrov an hour ago | parent [-]

That's great for primates, but what about nematodes? Everything with a nervous system sleeps, even when the cost is high.

	▲	redox99 30 minutes ago \| parent [-]
		Obviously sleep is necessary. I'm saying that there isn't always a large pressure to minimize sleep. Long sleep can be beneficial just to preserve energy.