• Defining fitness in evolutionary models

• Fulltext

https://www.ias.ac.in/article/fulltext/jgen/087/04/0339-0348

• Keywords

fitness; invasion exponent; adaptive dynamics; game theory; Lyapunov exponent; invasibility; Malthusian parameter.

• Abstract

The analysis of evolutionary models requires an appropriate definition for fitness. In this paper, I review such definitions in relation to the five major dimensions by which models may be described, namely

1. finite versus infinite (or very large) population size,

2. type of environment (constant, fixed length, temporally stochastic, temporally predictable, spatially stochastic, spatially predictable and social environment),

3. density-independent or density-dependent,

4. inherent population dynamics (equilibrium, cyclical and chaotic), and

5. frequency-dependent or independent.

In simple models, the Malthusian parameter ‘𝑟’ or the net reproductive rate $R_0$ may be satisfactory, but once density-dependence or complex population dynamics is introduced the invasion exponent should be used. Defining fitness in a social environment or when there is frequency-dependence requires special consideration.

• Author Affiliations

1. Department of Biology, University of California, Riverside, CA 92521, USA

• Editorial Note on Continuous Article Publication

Posted on July 25, 2019