This book covers topics from a wide variety of disciplines including cell biology, developmental biology, ecology, endocrinology, genetics, molecular biology, neurobiology, and pharmacology . There is a focus on circadian (daily), tidal, seasonal, and annual rhythms, as well as other biological rhythms. Rhythms are placed within the context of the functional significance of these rhythms for the health and well-being of relevant organisms and include genetic and molecular mechanisms of biological timekeeping, melatonin and pineal gland rhythms, as well as on the chronobiology and chronotherapy of cardiovascular, pulmonary, ulcer, and other diseases.