Contributions of reproductive and dispersal evolution to the spatial spread of cane toads and other invasive species
University of California, Davis
An emerging paradigm in population biology is that evolutionary change can happen rapidly enough to influence population dynamics, which have traditionally been thought to occur on a much faster timescale than evolutionary change. Many empirical examples underlying the rapid evolution paradigm involve exotic species invasions, as invasive species are subject to strong, novel selection pressures upon introduction to their new environments. An ecologically and economically important aspect of invasions that rapid evolution may influence is the rate at which invasive species spread across space. I will present analytical approximations and numerical analyses of models comprised of partial differential equations and integro-difference equations that answer the following questions: 1) How does rapid evolution alter invader spread rates? 2) Are observed rates of evolution rapid enough to have meaningful impacts on the timescale of invasive species spread? 3) What are the relative contributions to changes in spread rate from evolution in traits related to reproduction and dispersal? I will conclude by showing how these models can be used to account for rates of cane toad spread across northern Australia.