Dissertation Research: Processes of Diversification and Evolutionary History of Web-toed Salamanders (Genus Hydromantes)

这个项目的目的是了解导致内华达州两种蹼趾蝾螈之间分歧的进化过程。一种是广布种（Hydromantes platycephalus），另一种（H. brunus）仅限于一个小区域，并且物种在形态和栖息地上显示出差异。遗传学证据表明，分布范围有限的物种可能是最近才从广布物种中分化出来的，而广布物种的不同部分已经相互隔离了数百万年。过去的气候变化和地质过程对这些物种内部和之间的遗传分化的相对影响将使用各种不同的遗传标记，结合分布modelling.These蝾螈提供了机会，研究一些人口与惊人的遗传分化水平，但高形态相似性，和其他形态分歧，但遗传相似。研究气候变化和地理障碍在塑造这些物种内遗传分化的分布和模式方面的相对作用，将进一步加深我们对谱系和物种形成的理解，这是进化生物学的一个主要焦点。更多地了解神秘的生物多样性和物种对过去环境变化的反应，对于保护工作也很有价值，特别是在未来气候变化可能产生的影响方面。

The aim of this project is to understand the evolutionary processes that have led to divergence between two species of web-toed salamanders in the Sierra Nevada. One species (Hydromantes platycephalus) is widespread and the other (H. brunus) is restricted to a small area, and the species show differences in morphology and habitat. Genetic evidence indicates that the range-restricted species may have recently diverged from the widespread species, and that different segments of the widespread species have been isolated from one another for millions of years. The relative influence of past climate changes and geological processes on genetic divergence within and between these species will be investigated using a variety of different genetic markers, in combination with distributional modeling.These salamanders offer the opportunity to study some populations with striking levels of genetic divergence but high morphological similarity, and others that are morphologically divergent but genetically similar. Examining the relative roles of climatic changes and geographic barriers in shaping the distributions and patterns of genetic divergence within these species will further our understanding of how lineages and species form, a major focus of evolutionary biology. Increased knowledge of cryptic biodiversity and species' responses to past environmental change will also be valuable for conservation efforts, especially with respect to the probable impact of future climate change.