DISSERTATION RESEARCH: Remnants of a Diverse Past: Assessing the Phylogenetic position of recently extinct Pleurocerid snails (Gastropoda: Pleuroceridae)

侧角螺科（Pleuroceridae）的淡水螺类具有高度的保护优先权，但对它们的生物学知之甚少。该项目的目的是推断Leptoxis（11个现存物种和13个灭绝物种）和最近灭绝的Gyrotoma（6个灭绝物种）的进化关系，以帮助定义生物相关的保护单位。线粒体和核DNA序列的现存和最近灭绝的Leptoxis和Gyrotoma将被用来推断它们的进化关系。存放在自然历史博物馆的贝壳的干燥组织将用于获取灭绝物种的DNA。除了现存物种外，还包括灭绝物种，这将增加本研究得出的进化假说的稳健性。 这将是第一个包括所有Leptoxis和Gyrotoma物种的进化研究。水生生态系统对社会的健康至关重要，但这些系统受到高水平的人为压力。美国东南部水资源的健康取决于这些系统中的基石物种pleurocerid蜗牛的持续生存。在过去的50年里，由于13种Leptoxis物种已经灭绝，Leptoxis属提出了特殊的保护问题。该项目将通过帮助确定管理单位，最终提高钩端螺旋体保护计划的有效性。

Freshwater snails of the family Pleuroceridae are of high conservation priority, but little is known about their biology. The objective of this project is to infer the evolutionary relationships of Leptoxis (11 extant and 13 extinct species) and the recently extinct Gyrotoma (6 extinct species) in order to aid in defining biologically-relevant conservation units. Mitochondrial and nuclear DNA sequences of extant and recently extinct Leptoxis and Gyrotoma will be used to infer their evolutionary relationships. Dried tissue from shells that were deposited in natural history collections will be used to obtain DNA of extinct species. Inclusion of extinct species, in addition to extant species, will increase the robustness of evolutionary hypotheses resulting from this study. This will be the first evolutionary study that includes all Leptoxis and Gyrotoma species.Aquatic ecosystems are essential to the health of society, but these systems are subject to high levels of anthropogenic stress. The health of water resources in the southeastern U.S. depends on the continued survival of pleurocerid snails which are cornerstone species in these systems. The genus Leptoxis presents special conservation concerns as 13 Leptoxis species have gone extinct in the last 50 years. This project will ultimately increase the effectiveness of conservation plans for Leptoxis by aiding in the definition of management units.