This paper reports on a series of computer simulations designed to examine some population genetic correlates associated with the stochastic fixation of novel chromosomal rearrangements appearing in small isolated populations as specified by the cascading speciation model. Simulated populations were subjected to repeated bottleneck events for 100 breeding periods, with electrophoretic data being input from allele frequencies published for the chromosomally polytypic lizard Sceloporus grammicus (the complex for which the cascade model was formulated). These data were used to calculate several population genetic correlates over the duration of the simulations. When bottleneck sizes consisted of five individuals, extinction rates were high, but 1-2.5% of the populations survived and fixed new chromosomal rearrangements. The electrophoretic profile for this population structure reflected D and F1s values nearly an order of magnitude higher than those calculated from natural populations. As founder populations are increased to 10 and 20 individuals, extinction rates decline, as do probabilities for fixing the novel rearrangements. D and F,s values approximate those characteristic of natural populations of S. gi-ammficus for founder populations of 20 animals. Fsr values remain high through all simulations. Within the constraints of the model, the cascading chromosomal speciation hypothesis proposed to explain the karyotypic diversity within S. g, ammicus appears unlikely.