DISSERTATION RESEARCH: Divergent selection and behavioral isolation due to anthropogenic ecosystem fragmentation

Recent research conducted in natural ecosystems has demonstrated that shorter, decadal, timescales are relevant for the study of evolutionary processes in wild populations. Such rapid evolutionary changes have been discovered in a wide range of species, many of which are of economic and ecological importance (e.g., commercially valuable fish and agricultural pests). Consequently, human-driven ecological changes such as climate change, pollution, extinction, and overexploitation are increasingly implicated as agents of evolutionary change. One emerging result of this burgeoning research direction is that animal communication systems, such as those used in mate choice, predator detection, and species identification, are particularly sensitive to anthropogenic ecosystem alterations. This study addresses how communication systems are evolving due to altered ecological conditions. Data such as those generated by this study are critical for the advancement of a more integrated understanding of wild populations on an increasingly human-dominated planet. Integrating scientific research and education is also an important component. Education programs, and the development of field-based environmental courses, will build from long-term collaborative relationships with stakeholders such as local Bahamian NGOs (e.g., Friends of the Environment) and directly supports continuation and expansion of programs dedicated to the dissemination of conservation information and science relevant for contemporary and emerging environmental management scenarios in the United States and abroad.

This study will address the role of terrestrial anthropogenic ecosystem changes in altering the evolution of aquatic fish communication systems in which the evolutionary interests of the signaler (typically male) and the receiver (typically female) diverge. In these types of systems conflicting interests select for males to exploit existing female preferences by exaggerating their signals and for females to discriminate against such males. Importantly, exploitation by signalers, and the stability of the communication system, is theorized to be kept in check by high ecological costs, such as predation risk, paid by low quality males that exaggerate their signals (costs of lying). This research will evaluate this prediction using a series of coastal wetlands in which predators have been extirpated due to habitat fragmentation. Specifically, two hypotheses are tested: 1) anthropogenic predator extirpation (and thus lower costs of dishonesty) will cause increased rates of dishonest signaling in males, and 2) the strength of female preference will be positively correlated with the degree of male dishonesty. In essence, we predict that anthropogenic predator extirpation will result in higher rates of male dishonesty and a decrease in female preference for those signals representing the erosion of a functional communication system.