DISSERTATION RESEARCH: Evolutionary Diversification and Community Assembly in Melanesian Forest Frogs: Testing the Hypothesis of Replicated Adaptive Radiation

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Understanding the mechanisms that generate and regulate biodiversity patterns can provide broad insights into how biological communities assemble and diversify over different timescales. The importance of evolutionary processes for the generation of biodiversity in isolated island systems is well documented. However, the question remains: can processes like speciation and adaptation lead to predictable outcomes during the assembly of biological communities on islands? This study aims to address this question by examining patterns of frog diversity in the Melanesian island archipelagos of the Southwest Pacific. Melanesian forest frogs provide an ideal system to study adaptive processes of diversification because they are distributed across multiple island chains and exhibit a similar set of habitat specialists (ecomorphs), which are unique to each island group. This study will test the hypothesis that these ecologically similar frog communities evolved independently in each archipelago, resulting in the convergence of entire species communities. This project will document a remarkable case of convergent evolution that could provide additional evidence bearing on the evolution and assembly of biological communities worldwide. Portions of this research will also include advanced undergraduate mentoring in science, including genomic sequence capture data collection and analysis. Additionally, the results of this project will be integrated into a classroom learning module geared toward teaching evolutionary concepts to Kansas high school students.A major goal of this study is to resolve the evolutionary relationships among Melanesian Forest Frogs of the genus Cornufer using an exon capture sequencing approach. Phylogenomic data will be integrated with morphometric and ecological data from all species throughout the Melanesian archipelagos to test whether (1) frog ecomorph communities evolved in each archipelago through independent adaptive radiations, (2) ecomorphs evolved only once and subsequently dispersed across archipelagos, or (3) a combination of both. Macroevolutionary models will then be used to evaluate whether frog communities in each archipelago are more or less ecomorphologically convergent that expected by chance, which may suggest that adaptive diversification and community assembly has been nonrandom in Melanesian Forest Frogs. This study will promote the development of another rich, multi-faceted model system of adaptive radiation for a variety of conceptual evolutionary studies on the process of biological diversification and community assembly.