RUI: Cladistic Biogeography of Endemic Herpetofauna in Southern Africa

9707568兰姆生物地理学研究地球历史对生命多样化的影响。隔离在这种多样化中起着关键的初始作用：地理上与其他生物分离的生物群体具有自己的系统发育和生物学轨迹。长期地理隔离的一个潜在影响是受限制的或孤立地区特有的独特物种的分化（起源）（例如，澳大利亚的有袋动物）。在这项研究中，兰姆和鲍尔将研究地质和气候事件在形成南部非洲蜥蜴中观察到的广泛的区域地方性特征方面所起的作用。为了评估区域性事件对蜥蜴多样性的影响，他们将利用超过2000个碱基对的DNA序列（从三个线粒体基因中取样）和一套形态特征来构建五个不同蜥蜴属的谱系或系统发育树（拓扑）。然后比较五种不同的拓扑结构在整体形状上的相似性（一致性），以确定共同的模式和生物地理因素。这些蜥蜴类群的分化与中新世早期和上新世-更新世时期的大地构造事件和古气候变化有关的假设将得到检验。该研究还将为一些鲜为人知的分类群提供系统发育和分类信息。最后，本科生几乎在项目的每个阶段都有实质性的参与。

9707568 Lamb Biogeography addresses the influence of earth history on the diversification of life. Isolation plays a key inceptive role in this diversification: groups of organisms separated geographically from others assume their own phylogenetic and biological trajectory. One potential effect of long-term geographic isolation is the divergence (origin) of unique species that are restricted or endemic to an isolated area (e.g., marsupials in Australia). In this research, Lamb and Bauer will examine the role that geologic and climatic events have played in shaping the extensive regional endemism observed among lizards in southern Africa. To assess the influence of regional events on lizard diversity, they will utilize more than 2,000 base pairs of DNA sequence (sampled from three mitochondrial genes) and a suite of morphological characters to construct a genealogical or phylogenetic tree (topology) for each of five different lizard genera. The five different topologies will then be compared for similarities (congruence) in overall shape in order to identify common patterns and biogeographic factors. Hypotheses that divergence of these lizard taxa are linked to geotectonic episodes and paleoclimatic shifts in the early Miocene and Plio-Pleistocene periods will be tested. The research also will provide phylogenetic and classification information for several taxa that are poorly known. Finally, there is substantive involvement of undergraduate students in almost every phase of the project.