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

9310374例寄生虫可能负责维持繁殖模式，“红皇后”假说。在一些系统中，无性恋者比有性恋者有更多的寄生虫，但目前研究的初步数据显示正好相反。然而，使用这些数据作为红皇后假说的直接测试是不可能的，因为各种机制，如寄生虫传播动力学和毒力，可以塑造寄生虫在野外的分布模式。红皇后假说预测了在宿主/寄生虫相互作用中哪些机制是重要的，从而使无性生殖动物更受欢迎：i)宿主易感性必须是种群中寄生虫分布的最重要决定因素；Ii)宿主的易感性必须由基因决定；iii)宿主的易感性必须是频率依赖性的，随着时间的推移，最常见的基因型会变得最易感。目前的研究将在有性/无性壁虎系统中实验验证这些预测。了解主要人口统计学特性的维持和发展，如物种间的繁殖方式，是种群生物学的主要目标。%%%然而，理论预测孤雌生殖形式是罕见的，因为它们更容易受到寄生虫的影响，这在很大程度上仍未在复杂的生态环境中得到检验。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. ***