Title: Evolution of Dispersal in Patchy Habitats
Speaker: Laine Noble (OSU)
Abstract: We investigate whether a dispersal strategy resulting in ideal free distribution (“IFD strategy”) is convergent stable. Species compete using fixed dispersal strategies in a patchy habitat with spatially varying but temporally constant carrying capacities. Population growth in each patch is governed by a function which is assumed only to be monotone decreasing and differentiable. For two-patch habitat, we give a complete description of outcomes when any two strategies compete. We show that there is selection toward IFD strategy, but such a strategy is not convergent stable because selection may be disrupted by emergence of a joint IFD between two species. We show also that IFD strategy is not convergent stable in an n-patch habitat. We derive some extensions of the model to allow for species-specific carrying capacities and analyze those extensions in the context of unconditional dispersal in a two-patch habitat. We present some numerical results for the case of time-periodic carrying capacities.
Seminar URL: http://mgsa.org.ohio-state.edu/home.html