Dissertation Research: A Molecular Phylogenetic Study of Geographic Genetic Variation and Speciation in Salamanders of the Eurycea bislineata species complex

对于传播能力有限的与河流相关的生物，河流之间的历史联系可以预测种群之间的遗传相互作用和排水系统之间的传播路线。我们利用线粒体基因谱系的时空变异，研究了双线蝾螈（Eurycea bislineata）物种复合体中多齿蝾螈（plethodontid salamander）河流流域的地质历史与地理遗传碎片化之间的关系。在北美东部的内陆低地、阿巴拉契亚高地、皮埃蒙特和沿海平原地理省份，多齿蝾螈是常见的。对北美东部多齿蝾螈动物群的深入研究揭示了该种群中高水平的遗传结构和许多隐种，其特有性和物种多样性在阿巴拉契亚山脉南部比美国任何其他地区都要大。我们的研究提供了对影响这一物种丰富的脊椎动物群体多样化的历史因素的见解。在更广泛的层面上，这项研究对了解北美东部河流相关生物产生和维持生物多样性的因素具有重要意义。

For stream-associated organisms with limited dispersal abilities, the historical connections among streams generate predictions about genetic interactions among populations and routes of dispersal between drainage systems. We use the temporal and spatial variation present in mitochondrial gene lineages to investigate the relationship between the geological history of stream drainages and geographic genetic fragmentation in plethodontid salamanders of the Eurycea bislineata species complex. Plethodontid salamanders of the Eurycea bislineata species complex are common in streams throughout the Interior Lowland, Appalachian Highland, Piedmont and Coastal Plain physiographic provinces of eastern North America. Intensive research on the plethodontid salamander fauna of eastern North America has uncovered high levels of genetic structuring among populations and numerous cryptic species in this group, whose endemism and species diversity are greater in the southern Appalachian Mountains than any other region in the United States. Our research provides insight into the historical factors affecting diversification in this species-rich group of vertebrates. At a broader level, this research has implications for understanding factors that generate and maintain biodiversity in stream-associated organisms of eastern North America.