Introgression, recombination, and genomic differentiation in a cryptic species complex of North American passerines
department or school: Science, Faculty of
department or school: Zoology, Department of
data provider: DSpace
degree campus: UBCV
creator: Askelson, Kenneth
issued: 2023-12-18T22:05:35Z
issued: 2023
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Understanding how selection, recombination, and introgression interact during the speciation process is a key goal in the field of evolution, and many questions remain unanswered. In my dissertation, I make use of a cryptic species complex of white-breasted nuthatches (Sitta carolinensis) to understand the landscape of genomic differentiation between these putative species and how recombination and introgression have shaped those patterns. I then extend my findings regarding recombination and differentiation in white-breasted nuthatches to examine a broad sampling of genomic differentiation in avian species pairs, to infer how chromosome length (and thus rates of recombination) have shaped genome-wide patterns of differentiation. Through my research, I found that white-breasted nuthatches are comprised of four differentiated populations that are on a continuum of differentiation and that ghost lineage introgression has been involved in shaping these patterns. I also found evidence for large inversion-like haploblocks occurring in white-breasted nuthatches. I then combined these differentiation patterns with recombination estimates to show that broad-scale recombination rates are negatively associated with differentiation. In my final chapter, I found that the relationship between differentiation and chromosome length varied among pairs, but the direction of this relationship was significantly negatively correlated with the age of divergence. This result points to large chromosomes with lower rates of recombination being the likely areas to have higher amounts of differentiation in younger species. My dissertation spans a wide research scope, from species-specific questions to broad questions about recombination and differentiation. It expands our knowledge of bird species by describing the genomic patterns of this cryptic species complex and how ghost lineage introgression has provided important variation. My research also advances the field by adding to the growing…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/86976
note: Introgression, recombination, and genomic differentiation in a cryptic species complex of North American passerines by Kenneth Askelson B.Sc., The University of Wyoming, 2016 M.Sc., The University of British Columbia, 2018 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) December 2023 © Kenneth Askelson, 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: Introgression, recombination, and genomic differentiation in a cryptic species complex of North American passerines submitted by Kenneth Askelson in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Zoology Examining Committee: Darren Irwin, Professor, Zoology, UBC Supervisor Dolph Schluter, Professor, Zoology, UBC Supervisory Committee Member Judith Mank, Professor, Zoology, UBC University Examiner Sally Aitken, Professor, Forest and Conservation Sciences, UBC University Examiner Additional Supervisory Committee Members: Michael Whitlock, Professor, Zoology, UBC Supervisory Committee Member Loren Rieseberg, Professor, Botany, UBC Supervisory Committee Member iii Abstract Understanding how selection, recombination, and introgression interact during the speciation process is a key goal in the field of evolution, and many questions remain unanswered. In my dissertation, I make use of a cryptic species complex of white-breasted nuthatches (Sitta carolinensis) to understand the landscape of genomic differentiation between these putative species and how recombination and introgression have shaped those patterns. I then extend my findings regarding recombination and differentiation in white-breasted nuthatches to examine a broad sampling of genomic differentiation in avian species pairs, to infer how chromosome len…
has type: Thesis/Dissertation
date issued: 2023-05
is shown at: 10.14288/1.0438308
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: Irwin, Darren E
type: Text
identifier URI: http://hdl.handle.net/2429/86976