DISSERTATION RESEARCH: Co-estimating species responses to climatic variation in the Pleistocene using comparative phylogeography of closely related flying frogs across Sumatra

University Of Texas At Arlington, Arlington TX

Investigators

Abstract

This research investigates the evolutionary processes that have led to the extensive species diversity on two of the largest islands in Indonesia: Sumatra and Java. Very little is known regarding how species originated on these islands, but it is likely that past geologic and climatic events facilitated the diversification of plants and animals. This project will use genetic data to investigate how historical climate variation has influenced the diversification of twelve species of parachuting frogs (genus Rhacophorus). By using several species, this study will tease apart the common factors that influenced their diversification. Results will shed light on how species originate on islands, and provide broader insight on how changing climate affects species distributions and diversification. The project will train and mentor U.S. students, broadening participation in science by underrepresented groups, facilitating extensive international collaboration, and informing conservation practices. This research will test how Pleistocene climate variation influenced species distributions and diversification on Sumatra and Java. Using Rhacophorus flying frogs as a system, this project will utilize comparative phylogeography to co-estimate species assemblage responses to climate variation of both highland and lowland species. This study will employ an exon target capture approach to sequence ~1000 exons for twelve Rhacophorus species from Sumatra and Java. This project will test hypotheses of species expansions or contractions during the last glacial maximum using an Approximate Bayesian Computational model-testing approach. Using genomic data, the researchers will test for contraction in highland species, and expansion in lowland species as sea levels lowered, but forests contracted across the Sunda Shelf. Additionally, they will estimate a robust phylogeny for all Rhacophorus from Sumatra and Java, building upon previous mitochondrial and double-digest RADseq data generated for this project. The results of this study will complement previous studies investigating both Pleistocene climate-driven diversification in tropical forests, and tropical island diversification by revealing the assemblage-wide and species-specific processes that have driven diversification on the Sunda Shelf.