DISSERTATION RESEARCH: Genital biomechanics and mating system evolution in leiobunine harvestmen (Opiliones: Sclerosomatidae)

动物的生殖行为和结构极其多样，但这种多样性的功能和进化原因仍不清楚。多样化是由雄性和雌性之间的冲突驱动的，还是由雌性选择有价值的雄性特征驱动的？Shultz及其同事最近对一个有希望的模型系统--北美东部收割者（长腿叔叔）的研究发现，这些特征的组合与交配冲突的长期进化影响一致：生殖军备竞赛。 研究人员假设，收割者生殖结构的多样化是冲突的结果，而不是更广泛接受的雌性选择机制。这一假设将使用生物力学方法进行测试，以测量几个物种的雄性和雌性的关键物理变量。将使用严格的统计和定量比较方法来确定物种之间是否存在显著差异，以及雄性和雌性结构的力学参数是否共同变化。如果多样化是由于交配冲突，生殖结构应相关的能力，以提供和抵抗机械力，但这一结果不会被预期，如果男性性状的演变，由于女性的选择。 这项研究是生物力学在解释进化过程中的一个新应用，以及使用异常准确的定量数据进行比较。将为本科学员提供继续参与的机会。作为一名双胞胎少数民族科学家，Co-PI Burns的持续研究和指导有助于增加科学的多样性，并确保NSF先前对Co-PI Burns的投资将被证明是资源合理分配的。

Reproductive behaviors and structures in animals are extremely diverse, but the functional and evolutionary causes of this diversity remain unclear. Has diversification been driven by conflict between males and females or by female selection for valuable male traits? Recent work by Shultz and colleagues on a promising model system, the eastern North American harvestmen (daddy-long-legs), has identified combinations of features that are consistent with long-term evolutionary effects of mating conflict: a reproductive arms race. The researchers hypothesize that the diversification of reproductive structures in harvestmen is a result of conflict rather than the more widely accepted mechanism of female selection. This hypothesis will be tested using a biomechanical approach to measure key physical variables in males and females of several species. Rigorous statistical and quantitative comparative methods will be used to determine whether significant differences exist between species and whether the mechanical parameters of male and female structures co-vary. If diversification is due to mating conflicts, reproductive structures should be correlated in their abilities to deliver and resist mechanical forces, but this result would not be expected if male traits evolve due to female selection. This study is a novel application of biomechanics for the explanation of an evolutionary process, as well as the use of unusually accurate quantitative data for comparative methods. Opportunities for the continued involvement of undergraduate trainees will be provided. As a biracial minority scientist, the continued research and mentoring of Co-PI Burns serves to increase diversity in science and ensures that previous investments in Co-PI Burns by the NSF will prove to be resources well-allocated.