Given the marked variation in abiotic and biotic conditions between day and night, many
species specialise their physical activity to being diurnal or nocturnal, and it was long …

Early mammals were small and nocturnal. Their visual systems had regressed and they had
poor vision. After the extinction of the dinosaurs 66 mya, some but not all escaped the …

Most modern mammals, including strictly diurnal species, exhibit sensory adaptations to
nocturnal activity that are thought to be the result of a prolonged nocturnal phase or …

Mammalian life shows huge diversity, but most groups remain nocturnal in their activity
pattern. A key unresolved question is whether mammal species that have diversified into …

Temporal partitioning of activity among sympatric species can be an important mechanism
for species coexistence. Further, if exotic and native species overlap temporally, there is …

The landscapes of Madagascar have long delighted zoologists, who have discovered, in
and among the island's baobab trees and thickets, a dizzying array of animals, including …

The subtropical populations of owl monkeys (Aotus) and some lemurs have flexible patterns
that include activity during both day and night. Early studies on the activity patterns of …

Objectives Cross‐cultural sleep research is critical to deciphering whether modern sleep
expression is the product of recent selective pressures, or an example of evolutionary …

Objectives Primates vary in their sleep durations and, remarkably, humans sleep the least
per 24‐hr period of the 30 primates that have been studied. Using phylogenetic methods …

Activity patterns have profound implications on primates' morphology, physiology, and
behavior and have likely driven their diversification. The last common ancestor of extant …