Ecology of Adaptive Peak Shifts in Alaskan Threespine Stickleback (Gasterosteus aculeatus)
Abstract
Divergent natural selection is a major cause of phenotypic differentiation among populations exploiting different environments, but information on the ecological factors contributing to peak shift is largely missing from natural populations. Threespine stickleback (Gasterosteus aculeatus) is an emerging vertebrate model for studying phenotype-environment associations, as ancestral marine populations have adapted independently to postglacial freshwater environments. I characterized antipredator, foraging, and body shape phenotypes of 800+ fish from 16 ecologically diverse sites on the Alaska Peninsula. Gill rakers, antipredator traits, and body shape significantly associated with lake ecology, whereas foraging traits and body shape were influenced by geography. Stickleback from lakes ecologically similar to the ancestral state were more phenotypically similar to marine-influenced populations than fish from ecologically divergent habitats (i.e., small lakes). My study elucidates mechanisms associated with adaptive evolution and is one of relatively few that links ecological features of the adaptive landscape with phenotypic evolution in multiple populations.
Description
Keywords
Ecology
Citation
Vanderzwan, S. L. (2015). Ecology of Adaptive Peak Shifts in Alaskan Threespine Stickleback (Gasterosteus aculeatus) (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25781