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Evolutionary dynamics of fearfulness and boldness
Ting Ji1, Boyu Zhang, Yuehua Sun
1Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, PR China.
Life-history theory suggests a survival-reproduction trade-off. Evolutionary game theory reveals that neither fearfulness nor boldness is always favored; population size and density dynamics are crucial for understanding these survival strategies.
Area of Science:
- Evolutionary biology
- Life-history theory
- Game theory
Background:
- A negative relationship between reproductive effort and survival is a cornerstone of life-history theory.
- Understanding the evolutionary dynamics of survival and reproduction trade-offs is essential.
Purpose of the Study:
- To investigate the evolutionary dynamics and evolutionarily stable strategy (ESS) for the trade-off between survival and reproduction.
- To model these dynamics using two phenotypes: fearfulness and boldness.
Main Methods:
- Utilized a simple model to analyze the dynamical stability of pure strategies.
- Examined the conditions for evolutionarily stable strategy (ESS).
Main Results:
- The simple coexistence of fearfulness and boldness phenotypes is not possible.
- Small population size favors fearfulness, while large population size favors boldness.
- Neither fearfulness nor boldness is consistently favored by natural selection across all population sizes.
Conclusions:
- Population density dynamics are critical for understanding the evolutionary strategies of fearfulness and boldness.
- The interplay between population size and these behavioral phenotypes shapes evolutionary outcomes.
- The model highlights the context-dependent nature of natural selection on survival strategies.
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