Environmental impacts on hybridization outcomes
department or school: Science, Faculty of
department or school: Zoology, Department of
data provider: DSpace
degree campus: UBCV
creator: Kinney, Mackenzie
issued: 2023-08-23T20:48:20Z
issued: 2023
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Hybridization is the process of interbreeding between distinct genomic lineages. Environmental disturbances have been associated with increased hybridization between previously non-interbreeding lineages, suggesting that the production and survival of hybrids is influenced by the ecological conditions in which they occur. However, our understanding of hybridization, hybrid evolution, and the impact of natural selection on hybrid populations is limited compared to that of parent species. To address these gaps, my dissertation focused on investigating the effects of environmental changes on hybrid production and fitness, and the mechanisms driving the evolution of hybrid populations. Threespine stickleback fish served as a model for my thesis as they have diverged at least five times to form limnetic and benthic species capable of producing viable hybrid offspring. These species exhibit strong reproductive isolation and low hybrid fitness under natural conditions, but collapse into a hybrid swarm has been observed once in nature. In Chapter 2, I conducted experiments manipulating pond conditions to examine if eutrophication would disrupt reproductive isolation and influence hybrid survival as a consequence of reduced visibility and an altered ecological fitness landscape. Although our treatment did not appear to affect hybrid production or survival, we nonetheless observed an increase in hybrids independent of the treatment, highlighting the fragility of reproductive isolation in ecologically specialized species. In Chapter 3, inspired by the collapse of stickleback species in Enos Lake, I examined the fitness of F1 hybrids in the presence of crayfish. We observed a slight, but non-significant improvement in relative hybrid fitness as a consequence of changes in parent fitness. Chapter 4 focused on the evolution of three wild stickleback hybrid populations with varying proportions of parental ancestry inhabiting similar environments. We found parallel evolution in bot…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/85587
note: ENVIRONMENTAL IMPACTS ON HYBRIDIZATION OUTCOMES by Mackenzie Kinney B.Sc., The University of Waterloo, 2015 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in The Faculty of Graduate and Postdoctoral Studies (Zoology) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) August 2023 © Mackenzie Kinney, 2023 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Environmental Impacts on Hybridization Outcomes Submitted by Mackenzie Kinney in partial fulfilment of the requirements for forfor the degree of Doctor of Philosophy in Zoology Examining Committee: Dolph Schluter, Professor, Zoology, UBC Supervisor Darren Irwin, Professor, Zoology, UBC Supervisory Committee Member Catherine Wagner, Associate Professor, Botany, University of Wyoming External Examiner Amy Angert, Professor, Botany & Zoology, UBC University Examiner John Richardson, Professor, Forest and Conservation Sciences, UBC University Examiner Additional Supervisory Committee Members: Loren Rieseberg, Professor, Botany, UBC Supervisory Committee Member Mary O’Connor, Professor, Zoology, UBC Supervisory Committee Member iii Abstract Hybridization is the process of interbreeding between distinct genomic lineages. Environmental disturbances have been associated with increased hybridization between previously non-interbreeding lineages, suggesting that the production and survival of hybrids is influenced by the ecological conditions in which they occur. However, our understanding of hybridization, hybrid evolution, and the impact of natural selection on hybrid populations is limited compared to that of parent species. To address these gaps, my dissertation focused on investigating the effects of environmental changes on hybrid production and fitness, and the mechanisms driving the evolution of hybrid populations. Threespine stickleback fish served as a m…
has type: Thesis/Dissertation
date issued: 2023-11
is shown at: 10.14288/1.0435548
language: eng
degree discipline: Zoology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Schluter, Dolph
type: Text
identifier URI: http://hdl.handle.net/2429/85587