[noiv]

I like the idea of sleep as a consequence of information processing. At some point an organism needs to get rid of useless information acquired by its sensors previously. That's also why Maxwell's demon can't brake the second law of thermodynamics. Looking at people's behavior suffering sleep deprivation 'information overload' comes easily to mind. Perhaps the ability of REM sleep is a sign of some form of consciousness, which in turn is just an efficient way to process information and detect the useful bits.