Phenotypic structure and bifurcation behavior of population models

Discrete time models for density-regulated populations have been shown to exhibit periodic and chaotic motion in the absence of any external signal. We show how the genetic structure of a population can initiate bifurcations to periodic and chaotic trajectories. We investigate by simulation the dependence of this phenomenon on the strength of assortative mating, the level of heterozygosity, and the intensity of selection. The implications of internally generated chaos for population modeling are discussed.