- Russell G. Foster
- and Leon Kreitzman
‘Circadian rhythms: A 24-hour phenomenon’ explains the internally generated ‘clock’ that almost all living beings on Earth possess, which allows them to optimize a vast array of physiological processes and behaviour in advance of the varied demands of the daily solar cycle. Circadian rhythms are encoded in organisms’ genes, endogenously generated, and show near 24-hour rhythms in biological processes. They persist under constant conditions for several cycles, are entrained to the astronomical day via synchronizing zeitgebers, and show temperature compensation such that the period of the oscillation does not alter appreciably with changes in environmental temperature.