The rhythm of biological processes is an integral property of living matter. Living organisms for many millions of years live in conditions of rhythmic changes in geophysical parameters of the environment (change of seasons, change of day and night, etc.). Biorhythms are an evolutionarily fixed form of adaptation that determines the survival of organisms by adapting them to rhythmically changing environmental conditions. The fastening of these biorhythms ensured the anticipatory nature of the change in functions, i.e., functions begin to change even before the corresponding changes in the environment occur. The anticipatory nature of changes in functions has a deep adaptive meaning and significance, preventing the tension of the restructuring of body functions under the influence of factors already acting on it.
Biological rhythms are described at all levels, from simple biological reactions in the cell to complex behavioral reactions. Thus, a living organism is a combination of numerous rhythms with different characteristics.
The concept of “rhythm” is associated with the idea of harmony, organization of phenomena and processes. Translated from the Greek word “rhythm”, “rhythm” means proportionality, harmony. Rhythmic are natural phenomena that recur periodically. This is the movement of celestial bodies, the change of seasons, day and night, the frequency of tides. As well as the alternation of maxima and minima of solar activity.
Various physical phenomena are characterized by a periodic, undulating character. These include electromagnetic waves, sound, etc. In life, an example is the change in the atomic weight of elements, reflecting the sequential alternation of the chemical properties of matter. The basic rhythms in nature, which left their mark on everything living on Earth, arose under the influence of the rotation of the Earth in relation to the Sun, Moon and stars. The natural system is an open system, that is, subject to the influence of other natural systems. This means that the rhythms within one system can be determined by the rhythms of other systems through the interaction between systems.