title: Fitness costs in spatially structured environments.
abstract: The clustering of individuals that results from limited dispersal is a double-edged sword: although it allows for local interactions to be mostly among related individuals, it also results in increased local competition. Here I show that, because they mitigate local competition, fitness costs such as reduced fecundity or reduced survival are less costly in spatially structured environments than in nonspatial settings. I first present a simple demographic example to illustrate how spatial structure weakens selection against fitness costs. Then, I illustrate the importance of disentangling the evolution of a trait from the evolution of potential associated costs, using an example taken from a recent study investigating the effect of spatial structure on the evolution of host defense. In this example indeed, the differences between spatial and nonspatial selection gradients are due to differences in the fitness costs, thereby undermining interpretations of the results made in terms of the trait only. This illustrates the need to consider fitness costs as proper traits in both theoretical and empirical studies.
authors: Department of Zoology and Biodiversity Research Centre, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada. florence.debarre@normalesup.org.|Centre for Ecology & Conservation, University of Exeter, Penryn Campus, Penryn, TR10 9FE, United Kingdom. florence.debarre@normalesup.org.|Current address: Center for Interdisciplinary Research in Biology, CNRS UMR 7241, Equipe Stochastic Models for the Inference of Life Evolution, Collège de France, 11 place Marcelin Berthelot, 75231, Paris Cedex 5, France. florence.debarre@normalesup.org.
authors: Florence
authors: F
authors: Débarre
mesh_terms: D000818:Animals; D017753:Ecosystem; D019143:Evolution, Molecular; D056084:Genetic Fitness; D008957:Models, Genetic
keywords: Fitness costs; host defense; kin competition; spatial moment equations; viscous population