Foraging games and species diversity

We analyze a game theory model in which individuals foraging on a habitat c ontinuum choose behaviors that are the "best responses" to the behaviors an d densities of competitors. These behaviors determine community invasibilit y and coexistence. By making fitness an explicit function of maintenance me tabolic cost, we can show that changes in maintenance cost have an indirect but important effect on the best response behaviors, and hence, on communi ty dynamics. In particular, decreasing maintenance cost has the effect of d ecreasing habitat resource levels by increasing the efficiency with which i ndividuals convert resources into offspring. The resulting decrease in habi tat resource levels increases each phenotype's relative foraging advantage in whatever habitat(s) it holds an absolute advantage. As a result, more ph enotypes can successfully invade the community. Indeed, low enough maintena nce costs results in species inhabiting evolutionary minima in the adaptive landscape, which promotes disruptive selection and provides the potential for an evolutionary bifurcation.