biological periodicity
Quick Summary
Biological rhythms are periodic fluctuations in organisms that align with environmental changes, such as the cycle of day and night or tides. These rhythms are maintained by an internal mechanism called a biological clock, which continues to function even without external cues.12
A common type of biological rhythm is the circadian rhythm, which follows an approximately 24-hour cycle. This rhythm influences sleep, alertness, hormone release, and metabolism. The body's internal clock, primarily regulated by light signals detected by the eyes and processed in the brain, adjusts these cycles. Disruptions to these rhythms, like those experienced with jet lag, can cause fatigue and reduced efficiency. Other rhythms include monthly cycles, seen in marine organisms' reproduction, and annual cycles, affecting reproduction and growth in temperate zone plants and animals.341
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
- reproductive behaviourNatural selection and reproductive behaviour
…favourable rather than less favourable period will eventually dominate succeeding generations. This is the basis for the seasonality of reproduction among most animal species.
Read More…favourable rather than less favourable period will eventually dominate succeeding generations. This is the basis for the seasonality of reproduction among most animal species.
Read More - sexLife cycles adjusted to environmental change
…especially those of a regular seasonal character. This phenomenon is particularly striking in the case of the smaller or simpler forms of animal and plant life that have a life-span of a year or less. The seeds of annual plants germinate in the spring, grow and set seed in turn…
Read More…especially those of a regular seasonal character. This phenomenon is particularly striking in the case of the smaller or simpler forms of animal and plant life that have a life-span of a year or less. The seeds of annual plants germinate in the spring, grow and set seed in turn…
Read More
