Why species the world over sleep

However much some of us might crave some extra shut-eye, in the animal kingdom, sleep can be a dangerous time. Snoozing leaves us more vulnerable to predators and means we aren't up and around looking for food or mates. Scientists at the University of Wisconsin-Madison have a new hypothesis that might explain why species the world over sleep. A new study in the journal Neuron presents evidence that sleep is the price we pay for the ability to learn. Called the synaptic homeostasis hypothesis of sleep or "SHY", the researchers argue that brain connections may actually weaken during sleep. This allows the brain to conserve energy and 'reset' itself, allowing for more learning the following day. The scientists also cite evidence that sleep helps memory by allowing the brain to forget unimportant details. Viewing the primary function of sleep as decreasing the strength of connections between synapse and increasing signal-to-noise ratio challenges many of the existing theories on sleep and requires more testing to validate several hypotheses, but scientists say it may help explain one of life's most mysterious activities.