A dynamically coherent pattern of rhythms that matches between distant species across the evolutionary scale

Area of Science:

• Chronobiology
• Systems Biology
• Comparative Physiology

Background:

• Circadian and ultradian rhythms are fundamental to biological timekeeping, influencing behavior, physiology, and metabolism.
• Understanding the temporal organization of these rhythms is crucial for aligning biological processes with geophysical time.

Purpose of the Study:

• To investigate the temporal organization of circadian and ultradian rhythms across evolutionarily distant species.
• To identify common patterns in biological timekeeping from hours to minutes.

Main Methods:

• Development of a novel five-step wavelet-based approach for analyzing high-resolution time series data.
• Application of the method to analyze metabolism in yeast and behavior/metabolism in mice, rats, and quails.

Main Results:

• A dynamically coherent pattern of rhythms was observed across a broad range of temporal scales (minutes to hours).
• Key features of this pattern, including period splitting (e.g., 24h into 12h, 8h) and scale-free fluctuations below ~4h, were shared among yeast, mammals, and birds.
• Synthetic time series modeling supported the coexistence of multiple behavioral rhythms.

Conclusions:

• The study demonstrates a conserved, branching pattern of biological rhythms across diverse species.
• Circadian and ultradian rhythms are central to an emergent temporal organization in biological systems.
• This research provides new insights into the fundamental principles of biological timekeeping.