Genetics of Rapid Multivariate Evolution and Speciation

本项目利用湖泊三刺棘鱼（Gasterosteus aculeatus）种群的快速进化来解决两个进化问题。(1)遗传变异是否会影响进化的方向？遗传协方差矩阵（G矩阵）总结了湖泊种群及其海洋祖先的遗传性状变异和关联。G矩阵将相互比较，并与表型协方差矩阵（P矩阵）进行比较，P矩阵总结了总性状变异和关联。将分析G和P矩阵，以推断它们是否在后代湖泊种群中偏向于进化方向，并且G已经进化。(2)后代湖种群对生态条件的适应是否减少了后代与祖先种群的杂交，即后代是否是一个新物种？配偶选择实验将用于观察这些种群是否更喜欢自己种群的成员而不是其他种群的成员作为配偶。该项目将表明遗传变异是否会影响自然种群的进化，以及作为适应生态条件的副产品的新物种的形成。这将提高我们对棘鱼多样性和对新环境和物种形成的适应速度的理解，这对生物多样性的恢复具有重要意义。最后，它将促进阿拉斯加大学安克雷奇分校和石溪大学生物学家之间的合作，并为这两所大学的研究生和本科生提供研究经验。

This project exploits rapid evolution in a lake population of threespine stickleback fish (Gasterosteus aculeatus) to address two evolutionary questions. (1) Does genetic variation bias the direction of evolution? Genetic covariance matrices (G matrices), which summarize heritable trait variation and associations, will be computed for the lake population and its marine ancestor. The G matrices will be compared to each other and to phenotypic covariance matrices (P matrices), which summarize total trait variation and associations. G and P matrices will be analyzed to infer whether they have biased the direction of evolution within the descendant lake population and G has evolved. (2) Does adaptation to ecological conditions in the descendant lake population reduce interbreeding between the descendant and ancestral poulations, i.e., is the descendant a new species? Mate choice experiments will be used to see if these populations prefer members of their own population to those of the other as mates. This project will indicate whether genetic variation biases evolution of natural populations and new species form as a byproduct of adaptation to ecological conditions. It will improve our understanding of stickleback diversification and rates of adaptation to new environments and speciation, which have implications for restoration of biodiversity. Finally, it will facilitate collaboration between biologists at the University of Alaska, Anchorage and Stony Brook University and give graduate and undergraduate students at both institutions research experience.