Dissertation Research: The Evolutionary Persistence of Gynogenetic Lineages and the Role of Frequencey-Dependent Expression of Mating Behaviors

9701135 Hillis 最令人费解的遗传问题之一是克隆物种如何随着时间的推移维持自身状态。 雌核物种是克隆动物，由于繁殖依赖于另一个物种的雄性，因此面临着长期存在的障碍。 雌核发育物种不能孤立地持续存在。它必须与另一个能够在行为上寄生其雄性的物种共存。 然而，这种相互作用的简单种群模型预测雌核发育物种应该迅速灭绝。 雌核发生物种的存在表明这些模型不足以描述现实。 允许雌核发育物种持续存在的因素之一是频率依赖性行为。 这项研究将检查频率依赖性行为及其在雌核发育物种维持中的作用。 将构建一个包含频率依赖性配偶选择的数学模型，然后使用两种鳅鱼物种（雌核发育物种和它所依赖的物种）对该模型进行测试。 该模型将建立频率依赖性交配水平，理论上可以导致雌核发生物种及其所依赖的物种的稳定平衡。 这些实验将确定配偶选择是否依赖于频率，以及频率依赖是否足以解释雌核物种与其寄生物种的共存。

9701135 Hillis One of the more puzzling genetic questions is how clonal species maintain themselves through time. Gynogenetic species are clonal animals that face an obstacle to long-term persistence because reproduction is dependent on males of another species. A gynogenetic species cannot persist in isolation; it must coexist with another species whose males it is capable of parasitizing behaviorally. However, simple population models of such interactions predict that gynogenetic species should rapidly become extinct. The existence of gynogenetic species indicates that these models are an insufficient description of reality. One factor that would allow the persistence of the gynogenetic species is frequency-dependent behavior. This investigation will examine frequency-dependent behaviors and their role in the maintenance of gynogenetic species. A mathematical model will be constructed that incorporates frequency-dependent mate selection, and then the model will be tested using two species of poeciliid fish: the gynogenetic specie and the species upon which it depends. The model will establish the levels of frequency-dependent mating that theoretically can result in a stable equilibrium of a gynogenetic species and the species upon which it depends. The experiments will determine if mate selection is frequency-dependent and if frequency-dependence is great enough to explain the coexistence of gynogenetic species and the species they parasitize.