The genetic basis for evolution of moth sexual communication systems

North Carolina State University, Raleigh NC

Investigators

Abstract

Darwin pointed out that one potentially weak area in his theory of evolution by natural selection was the existence of complex traits, the components of which appear to be non-adaptive on their own. Gaining a better understanding the evolution of such traits at a quantitative level is still an important challenge. The proposed research will examine the genetic basis of moth sexual communication traits where a female produces a sex pheromone with a precise blend of a number of volatile compounds, and males are behaviorally responsive only to the blend of females of the same species. Mutant females that produce a novel blend and rare males with genes for responding to as yet non-existing blends appear to be selected against, so it is hard to understand how Darwinian selection could result in the thousands of diversified pheromones and moth species that we see today. Crosses between two moth species that utilize different pheromone blends will be used to identify the specific genes responsible for the differences between them in pheromone production and perception. As a next step, the controlling nucleotide changes will be determined and their fitness consequences measured. We will use our work on moth pheromone diversification as a means to educate the public about evolutionary processes that can result in complex traits that seem to have intermediate forms that are selected against. In addition to its inherent value to the field of biology, the knowledge of sexual communication genes could lead to development of new ways to control moth pests.