title: On the function of sleep.
abstract: It is proposed that sleep serves the function of maintaining immobility in animals at times when immobility is an optimum behavioural survival strategem. Sleep is of great evolutionary age and is always carefully tailored to the life-style of each animal; abundant in some species and absent from others. The survival advantages conferred on an animal by the power of sleep to schedule behaviour effectively may justify its existence and persistence in the evolution of species.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D000866:Antelopes / Q000502:physiology; D001717:Birds / Q000502:physiology; D002335:Carnivora / Q000502:physiology; D002415:Cats / Q000502:physiology; D002417:Cattle / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology; D002940:Circadian Rhythm; D004569:Electroencephalography; D005399:Fishes / Q000502:physiology; D006801:Humans; D007103:Immobilization; D007313:Insecta / Q000502:physiology; D051379:Mice / Q000502:physiology; D002679:Pan troglodytes / Q000502:physiology; D012104:Reptiles / Q000502:physiology; D012146:Rest; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology; D013997:Time Factors