US-Germany DDEP: Evolutionary consequences of Cenozoic climate change on African reptile diversification

历史气候变化是陆地脊椎动物多样性格局形成的主要驱动力。虽然大多数证据都是基于哺乳动物和鸟类，但另一个大群体-有鳞爬行动物（包括蛇和蜥蜴的分支）-的进化动力学仍然在很大程度上未被探索。对于这个博士论文增强项目，研究生克里斯蒂希普斯利，博士的指导下。巴里Sinervo，将调查历史气候变化对蜥蜴的一个大家庭，蜥蜴的进化的影响。与德国柏林自然博物馆的Johannes Müller博士合作，将使用比较系统发育方法来测试非洲蜥蜴多样化率、生态学和形态学的祖先变化之间的相关性。结果将与古气候数据进行比较，以确定分类和形态多样化是否是由新生代早期以来非洲的干旱化驱动的，或者是否有其他因素（例如，进化年龄，生态位，形态创新），决定物种丰富度在这个分支。虽然热带雨林往往被视为多样性的摇篮，这项研究的重点是沙漠作为爬行动物进化中心的重要性。这项工作的成果包括更好地了解分子进化速率变化的原因，对气候变化的形态反应，以及生态变量和生物多样性之间的相互作用。特别是对蜥蜴的研究将有助于填补气候影响文献中的分类学和地理空白，这将有助于与其他陆生脊椎动物进行比较，并了解具有非常不同生理特性（即冷血与温血）的动物如何应对气候变化。该项目的合作性质，跨越美国，欧洲和非洲，也为来自不同背景的人们提供了一个独特的机会，共同致力于全球气候变化问题，这是现在对生物多样性未来的主要关注。

Historical climate change is a major driving force shaping diversification patterns of terrestrial vertebrates. While most of this evidence is based on mammals and birds, the evolutionary dynamics of another large group - squamate reptiles (the clade including snakes and lizards) - remain largely unexplored. For this doctoral dissertation enhancement project, the graduate student Christy Hipsley, under the guidance of Dr. Barry Sinervo, will investigate the effects of historical climate change on the evolution of a large family of lizards, the Lacertidae. In collaboration with Dr. Johannes Müller at the Museum für Naturkunde in Berlin, Germany, a comparative phylogenetic approach will be used to test for correlations between ancestral shifts in diversification rates, ecology and morphology in African lacertid lizards. Results will be compared with paleoclimatic data to determine if taxonomic and morphological diversification has been driven by the aridification of Africa since the early Cenozoic, or if there are other factors (e.g., evolutionary age, ecological niche, morphological innovation) that determine species richness in this clade.While tropical rainforests are often viewed as cradles of diversity, this research focuses on the importance of deserts as centers of reptile evolution. Outcomes of this work include a better understanding of causes of variation in rates of molecular evolution, morphological responses to climate change, and the interplay between ecological variables and biodiversity. Research on lacertid lizards in particular will help to fill taxonomic and geographical gaps in the climate impact literature, which will be useful both for comparisons with other terrestrial vertebrates and to understand how animals with very different physiologies (i.e. cold versus warm blooded) respond to climate change. The collaborative nature of this project, spanning the United States, Europe and Africa, also presents a unique opportunity for people from diverse backgrounds to work together on issues surrounding global climate change, which is now a major concern for the future of biodiversity.