The rotation of the Earth around its own axis creates a fundamental challenge for life on this planet, related to the need of all living organisms to modify their physiology in accordance with daily variations in multiple geophysical properties, including light, temperature, and availability of nutrients. As a consequence, all domains of life have developed intrinsic timing systems (“biological...

Circadian clocks rhythmically coordinate biological processes in resonance with the environmental cycle. The clock function relies on negative feedback loops that generate 24-h rhythms in multiple outputs. In Arabidopsis thaliana, the clock component TIMING OF CAB EXPRESSION1 (TOC1) integrates the environmental information to coordinate circadian responses. Here, we use chromatin immunoprecipit...

The daily light-dark cycle governs rhythmic changes in the behavior and/or physiology of most species. Studies have found that these changes are governed by a biological clock, which in mammals is located in two brain areas called the suprachiasmatic nuclei. The circadian cycles established by this clock occur throughout nature and have a period of approximately 24 hours. In addition, these cir...

Avian behavior and physiology are embedded in time at many levels of biological organization. Biological clock function in birds is critical for sleep/wake cycles, but may also regulate the acquisition of place memory, learning of song from tutors, social integration, and time-compensated navigation. This relationship has two major implications. First, mechanisms of the circadian clock should b...

Sexual selection favours the expression of traits in one sex that attract members of the opposite sex for mating. The nature of sexually selected traits such as vocalization, colour and ornamentation, their fitness benefits as well as their costs have received ample attention in field and laboratory studies. However, sexually selected traits may not always be expressed: coloration and ornaments...

On moonless nights, the wakes of oceangoing boats sparkle with the blue bioluminescence of unicellular dinoflagellates. As a graduate student at Harvard University, Jay C. Dunlap pondered the carefully orchestrated biological rhythms that direct dinoflagellates to produce light only at night. Dunlap, a student of oceanography at the time, realized that the field of biological rhythms was still ...

In this chapter, we present a series of four articles derived from a Introductory Workshop on Biological Rhythms presented at the 72nd Annual Cold Spring Harbor Symposium on Quantitative Biology: Clocks and Rhythms. A diverse range of species, from cyanobacteria to humans, evolved endogenous biological clocks that allow for the anticipation of daily variations in light and temperature. The abil...