Despite decades of intense study, the functions of sleep are still shrouded in mystery. The
difficulty in understanding these functions can be at least partly attributed to the varied …

Sleep is a highly conserved state across the animal kingdom. However, sleep duration,
behavior and associated neural activity show great diversity across taxonomic groups, and …

During sleep, animals do not eat, reproduce or forage. Sleeping animals are vulnerable to
predation. Yet, the persistence of sleep despite evolutionary pressures, and the deleterious …

Why we sleep remains one of the enduring unanswered questions in biology. At its core,
sleep can be defined behaviorally as a homeostatically regulated state of reduced …

Many mammalian species, including humans, spend a substantial fraction of their life
sleeping. Sleep deprivation in rats ultimately leads to death, indicating the essential role of …

Here, we propose an original approach to explain one of the great unresolved questions in
animal biology: what is the function of sleep? Existing ecological and neurological …

The correlates of mammalian sleep have been investigated previously in at least eight
comparative studies in an effort to illuminate the functions of sleep. However, all of these …

Sleep is nearly ubiquitous throughout the animal kingdom, yet little is known about how
ecological factors or perturbations to the environment shape the duration and timing of …

Molecular and genetic approaches in several species have provided new insights into the
mechanisms of rest-activity and sleep-wake regulation. Many of these discoveries are …

The comparative methods of evolutionary biology are a useful tool for investigating the
functions of sleep. These techniques can help determine whether experimental results …