Functions of Sleep: Evolutionary Explanations

Evolutionary Explanations

• Energy Conservation
• Warm blooded animals need to expend a lot of energy to maintain a constant body temperature.
• Particularly problemativ with small animals.
• All activities use energy, animals with high metabolic rates use even more. 
• Sleep, provides a periof of enforced inactivity; hibernation.
• Foraging Requirements
• The time spent sleeping may be constrained by food requirements.
• Herbivores spend their time eating plant which are poor in nutrients.
• Must spend a great deal of time eating and not much sleeping.
• Carnivores can afford to sleep.
• Predator Avoidance
• Sleep is constrained by predation risk.
• Predator can sleep for longer; prey have to be vigilant for predators.
• Waste of Time
• Meddis proposed the waste of time hypothesis. Sleep helps animals stay out of the way of predators during the day.
• Sleeping furing the hours of darkness. and where they will be hidden.
• Sleep may ensure that animals stay still when they have nothing better to do with their time.
• Siegel says being awake is riskier than sleeping.
• Only possible explanations for sleep is that it enables both energy conservation and keeping an individual out of danger

Evaluation

• Energy, foraging…