Phylogenetic Analysis of Reproductive Isolation in Cyprinid Fishes

生物多样性是由物种形成过程产生的， 由阻止不同物种杂交的因素维持的 (i.e.生殖隔离）。生殖隔离是最 很容易在涉及小鱼的情况下进行研究 种，Luxilus cornutus和Luxilus chrysocephalus， 杂交 广泛分布在美国东部。 托马斯道林博士 亚利桑那州立大学一直在研究基因相互作用 在这两个杂交物种之间， 维持要素有效性的地理差异 生殖中断 这项研究扩展了道林博士的 以前的研究通过检查东部地区， 物种共存和邻近地区的西部和南部， 提供了地理变异的完整特征， 生殖隔离 线粒体序列变异 DNA控制区正在被用来推断系统发育 cornutus和chrysocephalus种群之间的关系， 识别 前更新世和后更新世的影响在构造的重要性 这些物种的遗传变异。 这些比较 与生殖隔离模式的关系将允许 为了测试祖先、传播和地质 生殖隔离地理变异的历史。 同样，人口统计学将允许审查 水文历史和扩散对 每个物种的遗传变异，提供了一个测试， 关于物种多样性起源的假说 中部高地地区，北部最多样化的动物群之一 美国参考

Biodiversity is generated by the process of speciation and maintained by factors preventing interbreeding of distinct species (i.e. reproductive isolation). Reproductive isolation is most readily studied in situations like that involving the minnow species, Luxilus cornutus and Luxilus chrysocephalus, which interbreed extensively in the eastern United States. Dr. Thomas Dowling of Arizona State University has been studying genetic interactions between these two hybridizing species, and he has identified geographic variation in the effectiveness of factors maintaining reproductive discontinuity. This study expands upon Dr. Dowling's previous research by examining eastern locations where the two species co-occur and adjacent areas to the west and south, providing complete characterization of geographic variation in reproductive isolation. Sequence variation of the mitochondrial DNA control region is being used to infer phylogenetic relationships of cornutus and chrysocephalus populations and identify the importance of pre- and post-Pleistocene effects in structuring of genetic variation within these species. Comparisons of these relationships with the pattern of reproductive isolation will allow for tests of the role of ancestry, dispersal, and geological history in geographic variation of reproductive isolation. Likewise, population phylogenies will allow for examination of the role of hydrographic history and dispersal on the distribution of genetic variation within each of these species, providing a test of hypotheses concerning the origin of species diversity in the Central Highlands region, one of the most diverse faunas in North America.