Pathwise thermodynamic structure in population dynamics.

Area of Science:

• Thermodynamics
• Population Genetics
• Evolutionary Biology

Background:

• Population dynamics are influenced by phenotype switching.
• Understanding mean fitness is crucial for evolutionary studies.
• Thermodynamic principles offer novel frameworks for biological systems.

Purpose of the Study:

• To reveal the thermodynamic structure underlying population dynamics with phenotype switching.
• To establish a variational principle for mean fitness in evolving populations.
• To represent the response of mean fitness to environmental and dynamic changes.

Main Methods:

• Applied large deviation theory to phenotype-switching dynamics.
• Utilized a thermodynamic variational principle.
• Analyzed the difference between time-forward and time-backward processes to assess selection strength.

Main Results:

• Demonstrated that mean fitness is governed by a thermodynamic variational principle.
• Expressed the response of mean fitness as a thermodynamic differential form.
• Quantified selection strength by comparing forward and retrospective dynamics.

Conclusions:

• Thermodynamic principles provide a powerful framework for understanding population dynamics and evolution.
• Phenotype switching can be effectively modeled using large deviation theory.
• The study offers new insights into the mechanisms of natural selection.