DISSERTATION RESEARCH: "Factors contributing to the morphological diversification of darters (Teleostei: Percidae)"

要提高保护现有生物多样性的能力，最好的办法是彻底了解造成物种数量（物种多样性）和这些物种所表现出的形状和大小的多样性（形态多样性）变化的因素。 为此，本研究定量研究形态多样化的速度和三个因素之间的关系，近亲之间的地理范围重叠的程度，物理栖息地的多样性，以及增加功能系统的复杂性的形态特征。 本研究使用的物种群内的谱系被称为镖鲈（真骨亚纲：Percusae）的北美淡水鱼，以检查每个因素之间的关系和形态多样化的速度。 由于这项研究明确探讨了近亲之间的地理范围重叠和形态多样化的速度之间的关系，结果将表明目前的保护方法，特别是人类介导的建立在新的地点的受威胁物种的种群，实际上诱导形态变化，而不是采取行动，以保持一个物种的形态在很长一段时间。 此外，研究结果不仅将提供有关镖鲈形态多样性的信息，还将表明这三个因素是否在其他动物和植物群体的形态多样性中起重要作用。

The ability to preserve existing biodiversity is best improved by a thorough understanding of the factors that cause changes in both species number (species diversity) and the variety of shapes and sizes exhibited by those species (morphological diversity). To this end, this research quantitatively examines the relationship between the rate of morphological diversification and three factors, extent of geographic range overlap among close relatives, the diversity of physical habitats occupied, and a morphological feature that increases the complexity of a functional system. This study uses groups of species within lineage of North American freshwater fishes known as darters (Teleostei: Percidae) to examine the relationship between each factor and the rate of morphological diversification. Because this study explicitly examines the relationship between geographic range overlap among close relatives and the rate of morphological diversification, the results will indicate whether current conservation methods, specifically the human-mediated establishment of populations of threatened species in new locations, actually induce morphological change rather than act to preserve a species' morphology over long periods of time. In addition, the results will not only provide information about the morphological diversification of darters, they will also suggest whether the three factors have been important in the morphological diversification of other groups of animals and plants.