Why do we sleep?

[Biscuit dunker]

Often thought about this.

I've read the stuff about why we need sleep from a biological point of view but never quite understood why we developed this need in the first place?

Do amoeba sleep?

Is it a fundamental requirement of all life-forms and if not, why did we develop the need in the first place?

Surely, applying Darwinian logic we'd have an advantage by never requiring sleep?

[Biscuit dunker]

Hoofy said:

Because it's nice.

x2.

But seriously, surely being able to stay awake and fully alert is an evolutionary advantage over needing to sleep to stay alert when awake?

[Biscuit dunker]

jogon said:

Biscuit dunker said:

x2.

But seriously, surely being able to stay awake and fully alert is an evolutionary advantage over needing to sleep to stay alert when awake?

Having done a few weekenders during my uni days, fri-sun with the help of many chemicals, I can assure you it does not result in any evolutionary superpowers.

Quite the opposite, sleep is essential.

Yes, but why have we developed this way? Surely eradicating sleep would be the prefered evolutionary direction?

Per my original question, do single cell critters need sleep? If not why do we and if so why didn't we evolve not to sleep? Always wondered about this one.

[Biscuit dunker]

Some good suggestions but doesn't really answer why.

Surely the optimum would be to not require sleep at all?

Dolphins don't sleep they just shut down bits of their brains. I'd have thought that by now we'd have 'evolved it out' of out makeup so we could go 24/7 (if you know what I mean..)

[Biscuit dunker]

Oakey said:

Biscuit dunker said:

Some good suggestions but doesn't really answer why.

Without it your brain goes into meltdown and you'll start hallucinating... horrible, horrible hallucinations.

I've read this but still don't understand why we (by we I mean the entire suite of biological organisms that prefigure ourselves in our evolutionary past) haven't evolved to the point where we don't need to sleep at all?

It's believed that dolphins don't actually sleep but shut down bits of their brain - how come we're not at the very least doing something similar? I don't need my entire brain to sit and watch the tv the OH forces me to watch every evening....

[Biscuit dunker]

blindswelledrat said:

No, because once upon a time calories were precious and starvation would have been a common killer. Being awake and alert uses up far more calories than being asleep and given that we can do nothing useful at night in the old days, then sleeping would be a major advantage.
Almost like a nightly hibernation

Now that, if it's true, actually makes sense in evolutionary terms - I hadn't really thought of it that way. Though, thinking about it, would it not be more efficient to be able shut down and save energy by choice rather than as an absolute necessity as is the case with sleep?