Seasonal changes in daylight help develop self-sustained daily body clocks

Self-sustained oscillation is rarer than damped oscillation and hourglass-type behavior in gene regulatory networks.

• Self-sustained oscillation is a key property of circadian rhythms observed in nearly all organisms.
• Environmental constraints and selection pressures may influence the evolution of self-sustainability in circadian oscillators.
• An evolutionary algorithm was used to optimize the structure of a gene regulatory network with light input pathways.
• Networks exhibiting self-sustainability achieved a significantly higher fitness score under constant periodic expression profiles.
• The findings suggest that seasonality may have played a role in the evolution of self-sustained circadian clocks.

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