Dissertation Research: Population Subdivision in Trimerotropis saxatilis (Acrididae)

本研究将探讨萨氏三足虫线粒体变异。这种蚱蜢在其分布范围内以细分的种群分布。生态实验已经确定种群规模比以前的遗传研究预期的要小，并且表明基因流动是不存在的。线粒体DNA是一种非重组分子，因此将构建线粒体单倍型的嵌套梯形图，并在各种水平上测试显着差异。估计基因流动和凝聚理论的间接方法将用于确定“历史事件”（如瓶颈）是否在过去发生，或者基因流动是否正在进行，但很少。将对整个萨氏滴虫范围内的种群进行取样，以便比较在范围的极端和中心发现的遗传变异。本研究除了对沙氏菌的特异性问题进行研究外，在保护遗传学领域具有广泛的应用前景。在过去的几千年里，由于气候的变化，萨萨林种群经历了栖息地破碎化。本项目开发和使用的统计方法可用于评估濒危物种的遗传状况。

This study will investigate the mitochondrial variation of Trimerotropis saxatilis. This grasshopper is found in subdivided populations throughout its range. Ecological experiments have determined that population size is smaller than expected from previous genetic studies and suggest gene flow is nonexistent. Mitochondrial DNA is a non-recombining molecule, so nested cladograms of mitochondrial haplotypes will be constructed and tested for significant differences at a variety of levels. Indirect methods of estimating gene flow and the coalescent theory will be used to determine whether "historical events" (e.g. bottlenecks) have taken place in the past or whether gene flow is ongoing, but rare. Populations throughout the range of T. saxatilis will be sampled in order to compare the genetic variation found at the extremes of the range to that in the center. Aside from questions pertaining specifically to T. saxatilis, this study has broader applications to the field of conservation genetics. T. saxatilis populations have undergone habitat fragmentation in the last few thousand years due to climate change. The statistical methods developed and used in this project can be used to assess the genetic status of endangered species.