Defining fitness in evolutionary models

  • Roff D
  • 122


    Mendeley users who have this article in their library.
  • 28


    Citations of this article.


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 (i) finite versus infinite (or very large) pop- ulation size, (ii) type of environment (constant, fixed length, temporally stochastic, temporally predictable, spatially stochas- tic, spatially predictable and social environment), (iii) density-independent or density-dependent, (iv) inherent population dynamics (equilibrium, cyclical and chaotic), and (v) frequency-dependent or independent. In simple models, the Malthu- sian parameter ‘r’ or the net reproductive rate R0 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-supplied keywords

  • Adaptive dynamics
  • Fitness
  • Game theory
  • Invasibility
  • Invasion exponent
  • Lyapunov exponent
  • Malthusian parameter

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • Derek A. Roff

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free