DISSERTATION RESEARCH: Tactic Switching, Habitat Selection, and Evolution of Alternative Mating Tactics

策略转换、栖息地选择与交配策略的演化。格雷戈里·f·格雷瑟和布伦达·拉里森自然种群如何保持变异是一个基本的进化问题。在变异的原因中，性选择起着突出的作用，导致了性状的夸大、交配策略的选择，甚至物种的形成。许多研究已经研究了不同物种的交配策略，这些物种的个体在大小或颜色等特征上表现出明显的差异，并且个体一生都使用一种策略。然而，大多数物种在这些特征上表现出连续的变化，个体表现出灵活的替代策略。一个重要的问题是，在这些条件下，可供选择的交配策略是如何演变的。除了表现出战术使用和身体特征的持续变化外，许多物种的个体还具有选择它们所利用的栖息地的能力。不同的栖息地促进了策略使用的差异，这可能进一步影响替代交配策略的进化。该研究将调查策略转换和栖息地选择是否促进了豆娘替代策略的进化和维持，其中策略使用与形状的持续变化有关。这一假设预测，1)策略的使用和适合度会随着环境和形状的变化而变化，2)雄性会根据自己的形状来选择环境。预测将通过观察、圈地实验、能量成本检查和动态状态模型的发展来检验。这个项目为美国学生和巴拿马当地学生提供了本科生研究的机会。

Tactic switching, habitat selection, and evolution of alternative mating tactics.Gregory F. Grether and Brenda LarisonHow variation is maintained in natural populations is a fundamental evolutionary question. Among the causes of variation, sexual selection plays a prominent role, leading to exaggerated traits, alternative mating tactics, and even speciation. Numerous studies have examined alternative mating tactics in species in which individuals exhibit distinct differences in traits such as size or color, and individuals use one tactic for life. However, most species exhibit continuous variation in such traits, and individuals exhibit flexible use of alternative tactics. An important question is how alternative mating tactics evolve under these conditions. Besides exhibiting continuous variation in tactic use and physical attributes, individuals of many species have the capability of choosing the habitats they utilize. Where different habitats promote differences in tactic use, this may further influence the evolution of alternative mating tactics.The proposed study will investigate whether tactic switching and habitat selection have promoted the evolution and maintenance of alternative tactics in a damselfly in which tactic use is associated with continuous variation in shape. This hypothesis predicts that, 1) tactic use and fitness should vary in response to environment and shape, and 2) males should select environments based on their shape. Predictions will be tested through observations, enclosure experiments, examination of energetic costs, and development of a dynamic state model. This project provides opportunities for undergraduate research for both U.S. students and local Panamanian students.