My research program investigated two interrelated phenomena: the evolution of aposematism (conspicuous warning signals) and Müllerian mimicry. Both of these phenomena involve the communication of unprofitability of prey to predators (or to potential mates) and both have been of interest to evolutionary biologists since the beginning of the Darwinian era. Despite this, many fundamental questions about these phenomena still remain.

My thesis research included two specific research efforts: (1) the investigation of aposematism and Müllerian mimicry using interactive computer simulations and (2) research on the unique case of intraspecific aposematism in the Coenagrionid damselflies. Through computer simulation experiments I asked questions about the conditions under which warning signals could have initially evolved, considering the fate of rare conspicuous mutants, the case in which mimicry by palatable species is possible (Batesian mimicry) and the interaction between the selection forces affecting the evolution of warning signals and prey aggregation. I also investigated the conditions under which selection for Müllerian mimicry was strong. Findings in these experiments included the importance of signal reliability on the evolution of warning signals, as well as the importance of chance effects in the establishment of rare conspicuous mutants. My research also revealed that Müllerian mimicry is most likely to evolve when a large number of prey species are present, such that it may be difficult for predators to remember each individual prey type.

Most species employ warning signals to advertise their unprofitability as prey to potential predators. But might warning signals function within species? It had been previously suggested that Coenagrionid damselflies, which are sexually dimorphic with brightly coloured males, display colour differences due to signaling between males, with bright coloration acting as a badge of maleness and thus warding off the unwanted approaches of other males. Here we tested some of the predictions of this theory, asking whether males showing different colours received increased harassment by conspecific males, and whether this harassment equates to some kind of cost. We have found that males displaying colours similar to females experience significantly higher harassment, though we did not detect a significant difference in survivorship related to this harassment.