Yin and Yang: Why did evolution implement and preserve the circadian rhythmicity?

Area of Science:

• Chronobiology
• Systems Biology
• Evolutionary Biology

Background:

• The Yin and Yang concept highlights the necessity of balance for living systems.
• Disrupting this equilibrium, through deficiency or excess, can upset homeostasis.
• Cells naturally tend to attenuate responses during prolonged exposure to substances.

Purpose of the Study:

• To present intermittent exposure as a stimulus for circadian rhythm development and conservation.
• To propose circadian rhythm as a counterbalance to cellular response attenuation.
• To explain the evolutionary advantage of circadian rhythms.

Main Methods:

• This is an opinion article, presenting a hypothesis.
• The study uses the Yin and Yang duality as an allegorical framework.
• It discusses the integration of circadian rhythmicity in human cells.

Main Results:

• Circadian rhythmicity is hypothesized to prevent the attenuation of cellular responses.
• This rhythm is integrated in most human cells, excluding stem and cancer cells.
• The Yin and Yang concept serves as an allegory for this balancing mechanism.

Conclusions:

• Circadian rhythmicity is proposed to have evolved as a mechanism to prevent disruption of homeostasis.
• It functions to maintain the organism's negative-feedback loops.
• This evolutionary adaptation is crucial for overall system balance.