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

历史气候变化是影响陆生脊椎动物多样性格局的主要驱动力。虽然这些证据大多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）的进化动力学在很大程度上仍未被探索。在本次博士论文强化项目中，研究生Christy Hipsley将在Barry Sinervo博士的指导下，研究历史气候变化对蜥蜴大家族Lacertidae进化的影响。在与德国柏林自然博物馆的Johannes m<e:1> ller博士的合作下，一种比较系统发育的方法将被用来测试非洲蜥的祖先在多样化率、生态和形态上的变化之间的相关性。研究结果将与古气候数据进行比较，以确定自早期新生代以来非洲干旱化是否推动了分类和形态多样化，或者是否有其他因素（如进化年龄、生态位、形态创新）决定了该支系的物种丰富度。虽然热带雨林通常被视为多样性的摇篮，但这项研究的重点是沙漠作为爬行动物进化中心的重要性。这项工作的结果包括更好地理解分子进化速率变化的原因，对气候变化的形态响应，以及生态变量与生物多样性之间的相互作用。特别是对蛇蜥的研究将有助于填补气候影响文献中分类学和地理学的空白，这将有助于与其他陆生脊椎动物进行比较，并了解生理上截然不同的动物（即冷血动物与温血动物）如何应对气候变化。这个横跨美国、欧洲和非洲的项目的合作性质，也为来自不同背景的人们提供了一个独特的机会，让他们在全球气候变化问题上共同努力，这是目前生物多样性未来的一个主要问题。

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.