Dissertation Research: Effect of phoretic dispersal on the structure of parasite populations

通过比较以不同方式传播的寄生虫种群遗传结构的差异，本研究将确定传播的增加和减少如何影响该结构。理解种群是如何以及为什么被构造的是进化生物学家的一个主要目标，因为由此产生的种群遗传结构会影响局部适应、物种形成和灭绝的速度。这项研究将研究生活在鸽子羽毛上的虱子的种群遗传结构。自然种群通常被细分，或遗传结构，因为地理或生态因素影响两个个体交配的机会。影响种群遗传结构的一个主要因素是扩散，即个体从一个地方迁移到另一个地方。当个体分散到新的种群中时，它们与新种群中的个体交配，从而减少种群遗传结构。我们对扩散如何影响这种结构的大小知之甚少。宿主-寄生系统提供了高度易处理的系统，用于研究不同的传播模式如何影响种群遗传结构。这项研究将通过检查位于同一宿主个体上的不同寄生虫物种的种群遗传结构来进行。此外，本研究还将以中学生为对象，开展“城市漫游指南：虱子的教训”的调查活动，并对研究生和本科生的培养做出贡献。在本研究中，研究人员将使用鸽虱、宿主-寄生虫系统，调查两种寄生羽虱的种群遗传结构的差异（目：Phthiraptera），它们的分散能力不同。本研究将探讨垂直扩散和水平扩散的作用，在结构化的翼虱和体虱发生在岩猪（Columba livia）的人口。 虽然这些虱子在生态学上非常相似，但翼虱可以通过苍蝇传播，而体虱则不然。尽管phoresy的普遍性，这种分散机制对这些生物的种群结构的影响是未知的。研究人员将使用巢式抽样设计从世界不同地区的不同宿主个体、不同群体中收集虱子。他们将在苍蝇存在的区域以及苍蝇不存在且不能发生电泳的区域进行采样。他们将使用微卫星数据来确定垂直和水平泳动扩散在构建虱子种群中的相对作用。

By comparing differences in the population genetic structure of parasites that disperse in different ways, this study will determine how increases and decreases in dispersal influence that structure. Understanding how and why populations are structured is a major goal of evolutionary biologists because the resulting population genetic structure affects rates of local adaptation, speciation and extinction. This study will examine the population genetic structure of lice that live on the feathers of pigeons. Natural populations are typically subdivided, or genetically structured, because geographic or ecological factors influence the chance that two individuals will mate. One major factor that influences population genetic structure is dispersal, the movement of individuals from one place to another. When individuals disperse to new populations, they mate with individuals in the new population reducing population genetic structure. We know little about how dispersal affects the magnitude of this structure. Host-parasite systems offer highly tractable systems with which to study how different modes of dispersal influence population genetic structure. This study will do so by examining population genetic structure of different parasite species that are located on the same host individuals. In addition, this study will produce an inquiry-based activity aimed at middle-school students, "Hitchhikers guide to the city: Lessons from lice," and will contribute to the training of graduate and undergraduate students.In this study, researchers will use a pigeon-louse, host-parasite system to investigate how population genetic structure differs between two species of parasitic feather lice (Order: Phthiraptera) that differ in their ability to disperse. The study will investigate the role of vertical dispersal and horizontal dispersal in structuring the populations of wing lice and body lice that occur on Rock Pigeons (Columba livia). Although these lice are ecologically very similar, wing lice can disperse phoretically using flies, whereas body lice do not. Despite the pervasiveness of phoresy, the affect that this dispersal mechanism has on the population structure of these organisms is unknown. Researchers will use a nested sampling design to collect lice from different host individuals, in different flocks, in different regions of the world. They will sample in regions where flies are present, and where flies are not present and phoresis cannot occur. They will use microsatellite data to determine the relative role of vertical and horizontal-phoretic dispersal in structuring louse populations.