DISSERTATION RESEARCH: A phylogenetic study of speciation in whirligig beetles

旋甲是水生甲虫的一个科，大约有1000种。所有的旋转甲虫都以非常相似的方式生活，但却表现出极大的形态多样性。如何解释这种行为和生活方式相似的甲虫家族的物种多样性呢？本研究试图确定生殖特征的选择是否是导致物种多样性的主要因素。这项研究将着眼于这些甲虫的许多生殖选择特征，然后使用系统发育树，比较相关的群体，看看是否有更多物种的分支也显示出更多的选择特征。要研究的特征之一是精子的形状。旋光甲虫精子表现出多种形式，并将这一群体精子的重建进化与物种形成率进行比较。长期以来，生殖特征的选择一直被认为是创造新物种的强大力量。然而，支持这一观点的研究很少着眼于大的进化尺度。对这一群体精子的研究可以用来检验先前建立的关于精子和雌性生殖道共同进化的假设，以及了解旋转甲虫精子的多样性，包括几种结合类型和各种大小。该项目将培养进化生物学方面的研究生，该研究生将指导几名系统学和节肢动物管理方面的本科生。确定的标本将被纳入新墨西哥大学，并纳入一个可公开访问的数据库，以加强研究和教育的基础设施。

Whirligig beetles are a family of aquatic beetles containing approximately 1,000 species. All whirligig beetles live in very similar ways, yet exhibit a great morphological diversity. What can explain the diversity of species in this family of beetles, who all behave and live in similar ways? This research attempts to establish if selection on reproductive traits has been a major factor in the evolution of this group leading to its diversity of species. The investigation will look at numerous reproductively selected features in these beetles, then using a phylogenetic tree, compare related groups to see if branches of the tree with more species, also show a larger number of selected traits. One of the traits to be studied is sperm shape. Whirligig beetle sperm show a diversity of forms and the reconstructed evolution of sperm in this group will be compared to the rate of speciation. Selection on reproductive traits has long been promoted as a powerful force for creating new species. However, few studies supporting this idea have looked at large evolutionary scales. The study of sperm within this group can be used to test previously established hypotheses about sperm and female reproductive tract co-evolution, as well as make known the diversity of whirligig beetle sperm, including several types of conjugation and a variety of sizes. This project will train graduate student in evolutionary biology and this student will mentor several undergraduate students in systematics and arthropod curation. Identified specimens will be accessioned at UNM and included in a publicly accessible database enhancing infrastructure for research and education.