Date of Award
Robin M. Tinghitella, Ph.D.
Divergent selection, Genetic divergence, Natural selection, Phenotypic divergence, Polymorphism, Sexual selection
Recent research has led to a much better understanding of the evolutionary processes that mold and structure variation within and among populations. How populations diverge at the genome-wide level and how polymorphism is maintained within a species, however, remains unclear. We address these questions with two freshwater color morphs, red and black, of the threespine stickleback fish (Gasterosteus aculeatus) from the northwest United States, in which a shift from red to black nuptial coloration occurred in several locations following glacial retreat. We measured phenotypic variation in a suite of traits and used next generation sequencing to characterize within-species and among-morph genetic variation between the two morphs. We found substantial phenotypic and genetic divergence between color morphs, and patterns observed in a third, "mixed" morph that are likely due to hybridization between anadromous and freshwater stickleback. This work highlights the central role of natural and sexual selection in the evolution of divergence in nature.
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Jenck, Clara Sophie, "Divergence of Threespine Stickleback That Differ in Nuptial Coloration" (2019). Electronic Theses and Dissertations. 1666.
Received from ProQuest
Clara Sophie Jenck
Ecology, Evolution & development