Dissertation Research: Parasites of Sexual and Asexual GeckoCongeners: Does Differential Parasitism Favor Sexuals?

9310374例寄生虫可能与生殖模式的维持有关，即“红女王”假说。在一些系统中，无性恋者的寄生虫明显多于有性恋者，但当前研究的试点数据显示出相反的模式。然而，不可能用这样的数据作为红后假说的直接检验，因为寄生虫的传播动态和毒力等各种机制可以塑造寄生虫在野外的分布模式。红皇后假说预测了哪些机制在宿主/寄生虫相互作用中必须是重要的，才能使无性恋者受到青睐：i)宿主敏感性必须是寄生虫在种群中分布的最重要决定因素；ii)宿主敏感性必须由基因决定；iii)宿主敏感性必须是频率相关的，随着时间的推移，最常见的基因型变得最容易受到影响。目前的研究将在有性/无性壁虎系统中对这些预测进行实验测试。了解主要人口统计特性的维持和发展，如物种间的繁殖方式，是种群生物学的主要目标。然而，预测孤雌生殖形式罕见的理论，因为它们更容易受到寄生虫的影响，在复杂的生态环境中很大程度上仍未得到检验。本研究从生态学的角度来研究进化生物学中的一个基本问题。***

9310374 Case Parasites maybe responsible for the maintenance of reproductive patterns, "Red Queen" hypothesis. In some systems asexuals have significantly more parasites than sexuals, but pilot data for the current studies show just the opposite pattern. However, it is impossible to use such data as a direct test of the Red Queen hypothesis since a variety of mechanisms, such as parasite transmission dynamics and virulence, can shape patterns of parasite distribution in the wild. The Red Queen hypothesis generates predictions about which mechanisms must be important in host/parasite interactions in order for asexuals to be favored: i) host susceptibility must be the most important determinant of parasite distribution in a population; ii) host susceptibility must be genetically determined; and iii) host susceptibility must be frequency-dependent, with the most common genotype becoming the most susceptible over time. The current study will experimentally test these predictions in the sexual/asexual gecko system. %%% Understanding the maintenance & development of major demographic properties, such as mode of reproduction among species, is a major goal of population biology. However, theory predicting that parthenogenetic forms are rare because they are more susceptible to parasites has largely remained untested in complex ecological situations. The present research takes an ecological perspective to a fundamental problem in evolutionary biology. ***