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Steady-state thermodynamics for population growth in fluctuating environments
Yuki Sughiyama1, Tetsuya J Kobayashi1
1Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8505, Japan.
Physical Review. E
|February 18, 2017
Summary
Population dynamics in fluctuating environments can be understood using thermodynamic principles. This study introduces a new framework to quantify excess population growth due to environmental changes, revealing an upper bound for this growth.
Area of Science:
- Ecology
- Theoretical Biology
- Statistical Mechanics
Background:
- Understanding population dynamics in unpredictable environments is crucial.
- Existing models often struggle to capture the effects of environmental fluctuations.
- Thermodynamic principles offer a potential framework for analyzing biological systems.
Purpose of the Study:
- To establish a mathematical equivalence between population dynamics in fluctuating environments and steady-state thermodynamics.
- To decompose population growth into 'housekeeping' and 'excess' components.
- To derive an inequality bounding excess population growth and identify conditions for achieving this bound.
Main Methods:
- Mathematical modeling based on thermodynamic principles.
- Decomposition of population growth into stationary and fluctuation-driven components.
- Derivation of a Clausius-type inequality for excess growth.
Main Results:
- Population dynamics in fluctuating environments exhibit a structure analogous to steady-state thermodynamics.
- Population growth is divided into housekeeping (stationary) and excess (fluctuation-induced) parts.
- A Clausius inequality was derived, providing an upper bound for excess growth, achievable under quasistatic environmental changes.
Conclusions:
- The study provides a novel thermodynamic framework for analyzing population dynamics under environmental fluctuations.
- Excess growth due to fluctuations is quantifiable and bounded.
- Lineage fitness, an observable quantity, can be used to evaluate the derived bound.
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