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

这项研究调查了导致印度尼西亚最大的两个岛屿苏门答腊岛和爪哇岛物种多样性广泛的进化过程。关于物种如何起源于这些岛屿，人们知之甚少，但很可能是过去的地质和气候事件促进了动植物的多样化。这个项目将使用遗传数据来研究历史气候变化如何影响到12种跳伞青蛙(树蛙属)的多样性。通过使用几个物种，这项研究将梳理出影响它们多样性的共同因素。研究结果将阐明物种如何起源于岛屿，并为气候变化如何影响物种分布和多样性提供更广泛的见解。该项目将培训和指导美国学生，扩大代表不足的群体对科学的参与，促进广泛的国际合作，并为保护实践提供信息。这项研究将测试更新世气候变化如何影响苏门答腊岛和爪哇的物种分布和多样性。利用树蛙作为一个系统，这个项目将利用比较系统地理学来共同估计高原和低地物种对气候变化的物种组合反应。这项研究将使用外显子靶标捕获方法对苏门答腊岛和爪哇的12种犀牛的~1000个外显子进行序列测定。该项目将使用近似贝叶斯计算模型测试方法来测试上一次冰川高峰期物种扩张或收缩的假设。利用基因组数据，研究人员将测试高原物种的收缩，以及随着海平面下降而低地物种的扩张，但整个舜达大陆架的森林正在收缩。此外，他们还将根据之前为该项目生成的线粒体和双酶切RADseq数据，估计苏门答腊岛和爪哇所有Rhacophorus的强大系统发育。这项研究的结果将补充先前对更新世气候驱动的热带森林多样化和热带岛屿多样化的研究，揭示推动舜达大陆架多样化的整个群落和特定物种的过程。

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.