Dissertation Research: Evaluating Indirect Estimates of Gene Flow: A Comparative Life History Approach

9423603海尔斯顿生物在自然种群之间的扩散程度已知会影响一系列生物事件，包括物种形成、灭绝和局部适应。基因扩散的遗传后果，称为基因流，通常从基因频率的地理分布中推断出来。然而，这种估计的准确性很难确定。测量在扩散能力不同的密切相关物种中的基因流，可以评估这种间接估计。这项建议概述了19种散布在一系列空间尺度上的天牛水螨的抽样制度。这些物种中的大多数在它们一生中只在水生昆虫的成虫阶段分散一次，而少数根本不分散。根据寄主的已知属性和寄主-寄生虫关系，可以对螨类物种的传播能力进行分类排名。从等位酶数据中分析每种螨类的遗传种群结构，以及一些昆虫寄主的种群结构。有关昆虫的数据将提供对寄生与寄生虫关联的遗传后果的洞察。对于水螨，将对扩散和基因流动之间的相关性进行统计评估，并将考虑系统发育关系。由于这些螨类密切相关，出现在相似的栖息地，而且它们的传播潜力已被很好地了解，因此它们之间除传播能力外的差异被最小化。这项研究将是第一次尝试评估一大群共存的、密切相关的物种的种群遗传结构。

9423603 HAIRSTON The magnitude of dispersal between natural populations of organisms is known to affect a wide array of biological events, including speciation, extinction, and local adaptation. The genetic consequence of dispersal, termed gene flow, is commonly inferred from the geographic distribution of gene frequencies. However, the accuracy of such estimates is difficult to ascertain. Measuring gene flow in closely related species which vary in dispersal ability allows such indirect estimates to be evaluated. This proposal outlines a sampling regime for 19 species disperse of Arrenurus water mites across a range of spatial scales. The majority of these species disperse only once in their lifetime on the adult stages of aquatic insects, while a few do not disperse at all. Dispersal ability of the mite species can be ranked categorically based on known attributes of the host and the host-parasite relationship. Analyses of genetic population structure will be made for each mite species from allozyme data, as will the population structure of some insect hosts. Data regarding the insects will provide insight into the genetic consequences of the parasitic association to the parasites. For the water mites, correlations between dispersal and gene flow will be assessed statistically, and phylogenetic relationships will be considered. Because these mites are closely related, occur in similar habitats, and their dispersal potential is well understood, differences between them other than dispersal ability are minimized. This study will be the first attempt to assess population genetic structure in a large group of co-occurring, closely related species.