The energy allocation (EA) model defines behavioral strategies that optimize the temporal
utilization of energy to maximize reproductive success. This model proposes that all species …

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 …

Phylogenetic and ontogenetic associations between sleep and endothermy are consistent
with the hypothesis that sleep evolved in conjuction with endothermy to offset the high …

Publisher Summary A vast amount of research on sleep has been generated during the past
two decades and much has been learned about its phenomenology and underlying …

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 phenomenon in endotherms, and therefore it must serve at least
one basic function across this wide range of species. What that function is remains one of …

The amount of time asleep varies greatly in mammals, from 3 h in the donkey to 20 h in the
armadillo. Previous comparative studies have suggested several functional explanations for …

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 …

Sleep function remains controversial. Individual perspectives frame the issue of sleep
function differently. We briefly illustrate how sleep measurement and the evolution, tissue …

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 …