How should we define fitness in structured metapopulation models? Including an application to the calculation of evolutionarily stable dispersal strategies

We define a fitness concept applicable to structured metapopulations consisting of infinitely many equally coupled patches. In addition, we introduce a more easily calculated quantity R-m that relates to fitness in the same manner as R-o relates to fitness in ordinary population dynamics: the R-m of a mutant is only defined when the resident population dynamics concierges to a point equilibrium and R-m is larger (smaller) than 1 if and only if mutant fitness is positive (negative). R-m corresponds to the average number of newborn dispersers resulting from the ton average less than one) local colony founded by a newborn disperser. Efficient algorithms for calculating its numerical value are provided. As an example of the usefulness of these concepts we calculate the evolutionarily stable conditional dispersal strategy for individuals that can account for the local population density in their dispersal decisions. Below a threshold density (x) over tilde, at which staying and leaving are equality profitable, everybody should stay and above (x) over tilde everybody should leave, where profitability is measured as the mean number of dispersers produced through lines of descent consisting of only non-dispersers.