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

进化的过程预计会有利于种群中最成功的单一行为策略，并消除不太成功的选择。然而，在一些物种中，雄性采取不同的行为策略来获得配偶，目前还不清楚雄性如何决定采用哪种策略，也不清楚这一决定可能产生的生殖后果。在黄粪蝇中，一些雄性在繁殖地争夺雌性，而另一些则在非竞争环境中寻找雌性。这项研究旨在了解环境和遗传因素对黄粪蝇雄性繁殖策略选择的影响，以及这些替代策略是如何在同一物种中保持的。这些结果将有助于解释在整个自然界中观察到的物种内动物特征的广泛多样性。此外，对生物学感兴趣的高中生和本科生将有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。身份相关的替代交配策略的共同出现是种群中持续存在的极端表型变异的一个例子。除了在获得配偶的行为和形态上的差异外，由于不同策略的雄性面临的配对竞争程度的不同，替代策略的雄性在生殖投资策略上也可能不同。理解这种表型变异的进化、维持和表达的合适的遗传模型长期以来一直是激烈辩论的主题。“环境线索阈值”模型最近作为一种强有力的基于数量遗传学的方法出现，用于研究这些长期存在的问题。然而，精确量化与每种战术相关的终身适合度的困难限制了它在实证研究中的应用。这项研究将通过使用模拟野外条件的大型实验围栏以及父子关系分配的分子分析来克服这些障碍，以评估与黄粪蝇替代交配策略的大小相关的寿命和繁殖成功，这是行为生态学的模式系统。从这项研究中获得的所有行为、形态和遗传数据都将被存入一个公共储存库，如仙女座。

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.