Ecological and Historical Determinants for Body Size Evolution: Insular/Mainland Contrasts in Three Reptile Systems in the Sea of Cortez

9318906案例 该项目测试的假设，生态相互作用是负责戏剧性的身体大小的变化，在三个独立的岛屿爬行动物系统：Sauromalus，Cnemidophorus，和响尾蛇在科尔特斯海，墨西哥。 体型变化的历史可以从种群间的系统发育关系中推断出来，如从核和线粒体DNA序列重建的那样。 这些历史信息被用来检验种群对竞争物种同域性的遗传反应的假设。 这项研究使用新的技术来测试长期存在的关于角色位移的假设。 这项研究是重要的，因为它允许重新评估一些经典的例子种群遗传反应的竞争（字符位移），并产生新的见解的角色竞争与捕食种群的遗传变化和结构的社区。 了解岛屿物种的生态相互作用的影响可以应用于小型孤立种群的保护和管理（例如，对引入的捕食者和竞争者的敏感性）。 本研究也为濒危物种立法的正确实施提供了科学依据。 ***

9318906 Case This project tests the hypothesis that ecological interactions are responsible for the dramatic body-size changes in three independent island reptile systems: Sauromalus, Cnemidophorus, and Crotalus in the Sea of Cortez, Mexico. The history of body size changes is inferred from the phylogenetic relationships among populations, as reconstructed from nuclear and mitochondrial DNA sequences. This historical information is used to test hypotheses of the population genetic response to sympatry with competing species. This research uses new technques to test long-standing hypotheses about character displacement. %%% This research is important because it allows re-evaluation of some of the classic examples of population genetic response to competition (character displacement) and yields new insights into the roles of competition vs. predation in the genetic change of populations and structure of communities. Understanding the effects of ecological interactions of island species can be applied to conservation and management of small isolated populations (e.g., sensitivity to introduced predators and competitors). This research also provides scientific background for sound implementation of endangered species legislation. ***