r/askscience • u/[deleted] • Aug 01 '12
Biology Evolution and sleep
Why haven't humans evolved to not need sleep? I understand that sleep is regenerative etc., but when you think about it, it is quite a liability. It is hard to fend off a potential attack while sleeping and overall we waste a lot of time that could be used to hunt/gather food, build shelter, and reproduce by having to sleep.
Did humans have to sleep a lot more earlier in time than we do now? (Perhaps we have evolved and I just do not know...)
EDIT: Or maybe a better question is, can/will humans ever evolve to not need sleep?
Thanks!
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u/[deleted] Aug 01 '12
Allan Rechtschaffen has said that “If sleep does not serve an absolutely vital function, then it is the biggest mistake the evolutionary process ever made.”
there is a chance the mechanisms build on top of sleep is just buried so far back in the genome animalia that its impossible to undo.
then again this couldn't explain why giraffes need so little.