- Russell G. Foster
- and Leon Kreitzman
‘Evolution and another look at the clock’ concludes that the circadian system controls every key aspect of biochemistry, physiology, and behaviour. All plants, fungi, protista, algae, invertebrates, vertebrates, cyanobacteria, and at least one archaeon display circadian rhythms. These rhythms have many molecular components conserved between diverse species and are thought to be generated by molecular transcription–translation feedback loops in which a group of core clock genes regulate each other to ensure that their mRNA levels oscillate with a period of approximately 24 hours. Although the empirical evidence has been difficult to demonstrate, there is a consensus that the internal clock has been of vital importance in the evolutionary history of living things.