Rapid Phenotypic Evolution and Speciation in a Lake Stickleback

University Of Alaska Anchorage Campus, Anchorage AK

Investigators

Abstract

Michael Bell, James Rohlf, Frank von Hippel DEB-0322818 Abstract GENETICS OF RAPID MULTIVARIATE EVOLUTION AND SPECIATION 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.