Barriers to Intraspecific Gene Flow Among Highly Divergent Salamander Lineages

本研究详细探讨了分布广泛的斑点蝾螈（Ambystoma maculatum）两个高度分歧的遗传谱系之间的有限基因交换的模式和过程。 在更新世的气候周期，斑点蝾螈种群被隔离在两个独立的避难所，导致高度分化的遗传种族。 这些种群随后扩大了它们的活动范围，形成了不同年龄和地理重叠的接触区。这项建议的主要目标是评估遗传隔离和随后的再接触的遗传后果，使用核DNA标记和收集沿沿着三个接触区。交配实验将被用来量化交配选择的模式和发生在谱系之间的遗传交换（或缺乏）的程度。生殖隔离的研究对我们理解分化和物种形成至关重要。 物种内部谱系之间的分歧可以是早期物种形成的例子，因此有助于我们理解最终导致新物种和生物多样性产生的过程。这项研究也有保护的影响，因为它记录了分布广泛的物种的遗传多样性的分布;信息至关重要的解释栖息地破碎化和新的接触区在这个和其他类群的遗传后果。

This research examines in detail the patterns and processes of limited gene exchange between two highly divergent genetic lineages in the widespread spotted salamander (Ambystoma maculatum). During the climatic cycles of the Pleistocene, spotted salamander populations were isolated in two independent refugia, resulting in highly divergent genetic races. These populations have subsequently expanded their ranges, resulting in contact zones of different ages and geographical overlap. The main goal of this proposal is to assess the genetic consequences of genetic isolation and subsequent re-contact using nuclear DNA markers and collections along three of these contact zones. Mating experiments will be used to quantify patterns of mate choice and the degree of genetic exchange (or lack thereof) that occur between the lineages.Studies of reproductive isolation are critical to our understanding of differentiation and speciation. Divergence among lineages within species can be examples of incipient speciation and therefore help us understand the process that ultimately leads to novel species and the generation of biodiversity. This research also has implications for conservation because it documents the distribution of genetic diversity in a widespread species; information crucial to interpreting the genetic consequences of habitat fragmentation and new contact zones in this and other taxa.