DISSERTATION RESEARCH: Evolution of Alternative Mating Tactics in the Yellow Dung Fly

进化的过程被认为有利于种群中最成功的行为策略，并消除不太成功的选择。然而，在一些物种中，雄性采用不同的行为策略来获取配偶，目前还不清楚雄性是如何决定采用哪种策略的，以及这种决定可能带来的生殖后果。在黄粪蝇中，一些雄性在繁殖地为获得雌性而相互竞争，而另一些雄性则在非竞争环境中寻找觅食的雌性。本研究旨在了解影响黄粪蝇雄性繁殖策略选择的环境和遗传因素，以及这些替代策略如何在同一物种内保持。这些结果将有助于解释在自然界中观察到的物种中动物特征的广泛多样性。此外，将为对生物学感兴趣的高中生和本科生提供机会，通过参与与这项工作相关的数据收集和分析来获得实践研究经验。地位依赖的替代交配策略的共存是种群中持续存在的极端表型变异的一个例子。除了在配偶保护行为和形态上的差异外，由于雄性面临的配子竞争程度的策略特异性差异，不同策略的雄性在生殖投资策略上也可能存在差异。长期以来，理解这种表型变异的进化、维持和表达的适当遗传模型一直是激烈争论的主题。“环境提示阈值”模型最近作为一种强大的基于定量遗传学的方法出现，用于调查这些长期存在的问题。然而，准确量化与每种策略相关的终身健康的难度限制了其在实证研究中的应用。本研究将通过使用模拟野外条件的大型实验围栏，以及对父权分配的分子分析来克服这些障碍，以评估黄粪蝇（Scathophaga stercoraria）替代交配策略的大小依赖性表达与寿命和繁殖成功相关，这是行为生态学的模型系统。从这项研究中获得的所有行为、形态和遗传数据将被存入公共存储库，如Dryad。

The process of evolution is expected to favor the single most successful behavioral tactic in a population and eliminate less successful options. Nevertheless, in some species, males adopt different behavioral tactics for acquiring mates, and it is unclear how males decide which tactic to adopt or what the reproductive consequences of this decision might be. In the yellow dung fly, some males compete with one another over access to females at breeding sites, whereas others search for feeding females in non-competitive environments. This study aims to understand the environmental and genetic factors that influence the choice of reproductive tactic in yellow dung fly males and how these alternative tactics are maintained within the same species. These results will help explain the wide diversity of animal traits observed within species throughout nature. Additionally, opportunities will be provided for high school and undergraduate students interested in biology to gain hands-on research experience by participating in data collection and analysis associated with this work.The co-occurrence of status-dependent alternative mating tactics is an example of extreme phenotypic variation persisting within a population. In addition to differences in mate securing behaviors and morphology, males of alternative tactics are also expected to differ in reproductive investment strategies due to tactic-specific variation in the degree of gametic competition that males face. The appropriate genetic model for understanding the evolution, maintenance, and expression of such phenotypic variation has long been the subject of intense debate. The "environmentally-cued threshold" model has recently emerged as a powerful quantitative genetics-based approach for investigating these long-standing questions. However, the difficulty of accurately quantifying lifetime fitness associated with each tactic has restricted its use in empirical studies. This research will overcome these obstacles by using large, experimental enclosures that simulate field conditions, as well as molecular analyses for paternity assignment, to assess lifespan and reproductive success associated with the size-dependent expression of alternative mating tactics in the yellow dung fly, Scathophaga stercoraria, which is a model system for behavioral ecology. All behavioral, morphological, and genetic data obtained from this research will be deposited into a public repository such as Dryad.