Speciation and hybridization in the Old World swallowtail butterfly (Papilio machaon) species complex

• Author / Creator

  Dupuis, Julian R

• Species delimitation is fundamental to evolutionary biology. However the process is far from straightforward in systems with complex evolutionary histories, and the concept of species as taxonomic hypotheses is often overlooked in many biological disciplines. Here I investigate species delimitation operationally, with a review and meta-analysis of the literature, and empirically, by investigating hybridization in swallowtail butterflies. First, I conducted a literature review on studies that used multiple molecular markers to delimit closely related species of animals and fungi. I evaluated the relative success of different types of molecular markers (mitochondrial, ribosomal, nuclear, and sex-linked genes) in delimiting closely related species and asked whether increased geographic or population-level sampling and the number of markers affected identification success. With this foundation, I then investigated hybridization in the Old World swallowtail butterfly (Papilio machaon Linnaeus, 1758) species complex. At a North America-wide scale, I assessed the putative hybrid origins of multiple lineages in the group, using morphology, mitochondrial DNA, microsatellites, and ecological characteristics. I then focused on a hybrid zone in southwestern Alberta and tested whether population genetic structure of the area (using mitochondrial DNA and microsatellites) was similar to an assessment done 30 years ago using morphology and allozymes. I also compared multiple hybrid identification and classification (F1, F2, backcross) methods for microsatellites and a genome-wide single nucleotide polymorphism dataset for a subset of individuals. Finally, I asked whether environmental or landscape variables could explain variation in genetic differentiation and interspecific hybridization in this hybrid zone, using spatial ecology and landscape genetics methods. This is the first application of raster-based landscape genetics methods to interspecific hybridization. Together, the progression of studies in this thesis provide important insight into species delimitation and add to a growing body of research documenting the complexity of hybridization, as well as its potential for generating biodiversity.

• Subjects / Keywords

  • Swallowtail butterfly
  • Speciation
  • Papilio machaon
  • Hybridization
  • Species complex

• Graduation date

  Spring 2016

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3CC0TZ7X

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.