Collaborative Research: Phylogenetic Analysis of G-matrix Evolution in the Repeated Adaptive Radiation of Anolis Lizards

本研究探讨了种群内个体间性状变异的遗传学基础，以及物种的遗传结构是如何进化的。由于性状受许多基因的影响，并且由于基因影响许多性状，不同性状的变异（例如，臂长和腿长）不是彼此独立的。遗传方差-协方差矩阵（G矩阵）总结了这些相互依赖性。本研究将估计八种阿诺利斯蜥蜴的G-矩阵。由于不同岛屿上的这些蜥蜴物种已经适应了相同的环境，这项研究将允许比较经历了相同自然选择压力的远亲物种，以及生活在同一岛屿上但经历了不同选择压力的近亲物种。这些比较将允许评估影响G矩阵如何演变的因素。G-矩阵在描述进化变化中具有根本的重要性，通过将一代的自然选择转化为下一代的表型变化。尽管如此，科学家们仍然没有很好地了解哪些因素影响G矩阵的进化。通过研究许多物种，这项研究将是迄今为止最广泛的研究，因此将大大扩展对进化变化背后的遗传学的理解。该项目将支持培训一名博士后学者、一名研究生和几名本科生，包括来自传统上代表性不足群体的学生。阿诺利斯蜥蜴已经成为研究进化多样化的主要模型之一，并将这种理解传递给广大观众。关于阿诺利斯进化的描述出现在无数的教科书、电视节目和流行出版物中。本项目将继续这些努力。

This study investigates the genetics underlying character variation among individuals within a population, and how the genetic structure of species evolves. Because characters are affected by many genes, and because genes affect many characters, variation in different characters (e.g., arm length and leg length) are not independent of each other. The genetic variance-covariance matrix (G-matrix) summarizes these interdependencies. This study will estimate the G-matrix for eight species of Anolis lizards. Because species of these lizards on different islands have adapted to the same environment, this study will allow the comparison of distantly related species that have experienced the same natural selection pressures, as well as closely related species that live on the same island, but have experienced different selective pressures. These comparisons will permit evaluation of the factors that affect how the G-matrix evolves. The G-matrix is of fundamental importance in describing evolutionary change by translating natural selection in one generation into phenotypic change in the next. Nonetheless, scientists still do not have a good understanding of what factors affect evolution of the G-matrix. By examining many species, this study will be the most extensive study to date and will thus greatly expand understanding of the genetics underlying evolutionary change. This project will support the training of a postdoctoral scholar, a graduate student, and several undergraduates, including students from traditionally underrepresented groups. Anolis lizards have become one of the major models for studying evolutionary diversification and relaying that understanding to a broad audience. Accounts of Anolis evolution have appeared in countless textbooks, television programs and popular publications. This project will continue those efforts.