Abstract:

We have constructed a database that describes the sleeping characteristics of 127 different mammalian species representing 46 families across 17 orders. The data were extracted from 178 separate references that were found using standardized search protocols, and for each study includes information on the time spent in REM and NREM sleep, sleep cycle length, the number of animals sampled, their sex and age, and reference citation. Importantly, we also coded nine laboratory condition scores as a way to control for the procedures that were used to collect the data. We created a website that contains the database (http://www.bu.edu/phylogeny/) from which others can both download the data and submit new results. This database is being used to address fundamental questions concerning the evolution of mammalian sleep; similar databases on other groups of organisms will enable sleep biologists to understand patterns of sleep at broader phylogenetic scales.