A bottleneck can occur when a new population is established from a few individuals. Bottlenecks have been invoked as a mechanism in the formation of new species because they may dramatically modify mating behavior, but the specific effects of bottlenecks on courtship repertoire have not been tested to confirm such a mode of speciation. Recent studies have shown that traditional models are inadequate to predict bottleneck effects on genetic aspects of complex traits, such as body size and survival. The proposed study will apply classical quantitative genetic techniques currently employed for morphology (i.e., statistical comparisons of body dimensions of parents and offspring) to examine the effects of bottlenecks on courtship behavior. Specifically, videotaped courtships of 100 families of each of twelve strains that have undergone population bottlenecks and four control lines of the housefly will be assayed for genetic variation and covariation of four courtship behaviors. These analyses will more clearly establish the efficacy of bottlenecks to alter the genetic properties of courtship elements and the consequent potential of bottlenecks to catalyze speciation. The successful management of endangered species critically depends upon such information for more thorough and accurate understanding of the effects of small population size on the genetics of reproductive behavior.
