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dc.contributor.advisor Robertson, Jeanne M en
dc.contributor.author Akopyan, Marjan en
dc.date.accessioned 2017-08-29T22:03:56Z
dc.date.available 2017-08-29T22:03:56Z
dc.date.copyright 2017 en
dc.date.issued 8/29/2017 en
dc.date.submitted 2017-08 en
dc.identifier.uri http://hdl.handle.net/10211.3/195233 en
dc.description Includes bibliographical references (pages 41-55) en
dc.description.abstract The processes that generate variation in nature have captured the attention of evolutionary biologists since the time of Darwin. Many studies examine the evolution of diversification in closely related or hybridizing species to understand the process by which new species evolve. However, more closely related divergent populations can provide a unique insight into how diversity evolves in nature. The Neotropical red-eyed treefrog (<i>Agalychnis callidryas</i>) exhibits substantial geographic variation on a relatively small spatial scale within Costa Rica and Panama, including differences in color pattern, body size, and skin peptide composition. Genetic analyses indicate ongoing gene flow among phenotypically differentiated populations, providing the opportunity to describe the patterns and processes that are integral to lineage divergence before isolation becomes complete. First, we tested the extent of behavioral premating isolation among differentiated populations by quantifying differences in male and female courtship signals. Our results show that both male advertisement calls and female behavior vary among populations, and that divergence in male signals is coupled with female preference for the local male phenotype. The interplay between male courtship and female responses may facilitate the evolution of local variants in courtship style, thus accelerating premating isolation via assortative mating. Second, we conducted a study of genomic and phenotypic variation across red-eyed treefrog populations, including a central contact zone. Our results indicate the creation of a distinct hybrid population at the contact zone. Association between geographic and genetic distance coupled with disassociation of genetic and phenotypic divergence indicate strong localized selection with high levels of genetic exchange. This study is one of few to characterize genome- wide divergence in a highly admixed intraspecific lineage, allowing us to describe the genomic architecture of diversification and infer whether evolutionary processes are driving and/or constraining divergence. We contribute to a growing body of knowledge on divergence with genetic exchange: gene flow is a dynamic evolutionary process that can simultaneously act as a creative, diversifying, and homogenizing force. en
dc.description.statementofresponsibility by Marjan Akopyan en
dc.format.extent xiv, 55 pages en
dc.language.iso en en
dc.publisher California State University, Northridge en
dc.rights.uri http://scholarworks.csun.edu/xmlui/handle/10211.2/286 en
dc.subject lineage diversification en
dc.subject courtship behavior en
dc.subject genomics en
dc.subject hybridization en
dc.subject sexual selection en
dc.subject anurans en
dc.subject red-eyed treefrogs en
dc.subject reproductive isolation en
dc.subject evolutionary biology en
dc.subject.other Dissertations, Academic -- CSUN -- Biology. en
dc.title Evolution of reproductive isolation: Genetic and phenotypic diversification in red-eyed treefrogs (Agalychnis callidryas) en
dc.type Thesis en
dc.date.updated 2017-08-29T22:03:56Z
dc.contributor.department California State University, Northridge. Department of Biology. en
dc.description.degree M.S. en
dc.contributor.committeemember Espinoza, Robert E en
dc.contributor.committeemember Gray, David A en
dc.contributor.committeemember Mackelprang, Rachel en
dc.rights.license By signing and submitting this license, you the author grant permission to CSUN Graduate Studies to submit your thesis or dissertation, and any additional associated files you provide, to CSUN ScholarWorks, the institutional repository of the California State University, Northridge, on your behalf. You grant to CSUN ScholarWorks the non-exclusive right to reproduce and/or distribute your submission worldwide in electronic or any medium for non-commercial, academic purposes. You agree that CSUN ScholarWorks may, without changing the content, translate the submission to any medium or format, as well as keep more than one copy, for the purposes of security, backup and preservation. You represent that the submission is your original work, and that you have the right to grant the rights contained in this license. You also represent that your submission does not, to the best of your knowledge, infringe upon anyone's copyright. If the submission contains material for which you do not hold copyright, or for which the intended use is not permitted, or which does not reasonably fall under the guidelines of fair use, you represent that you have obtained the unrestricted permission of the copyright owner to grant CSUN ScholarWorks the rights required by this license, and that such third-party owned material is clearly identified and acknowledged within the text or content of the submission. If the submission is based upon work that has been sponsored or supported by an agency or organization other than the California State University, Northridge, you represent that you have fulfilled any right of review or other obligations required by such contract or agreement. CSUN ScholarWorks will clearly identify your name(s) as the author(s) or owner(s) of the submission, and will not make any alterations, other than those allowed by this license, to your submission. en


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