Phylogenomic analyses clarify butterfly species within the genus Speyeria despite evidence of a recent adaptive radiation

Author

Erin Thompson, University of the PacificFollow

Date of Award

2019

Document Type

Thesis

Degree Name

Master of Science (M.S.)

Department

Biological Sciences

First Advisor

Ryan I. Hill

First Committee Member

Ajna S. Rivera

Second Committee Member

Zachary R. Stahlschmidt

Third Committee Member

Jason Baumsteiger

Abstract

The North American genus Speyeria is an especially challenging radiation of butterflies due to ongoing hybridization, incomplete lineage sorting, and similar morphological characters among species. Adaptive radiations often require considerable evidence in order to resolve the evolutionary relationships of closely related individuals. Previous studies of this genus have found paraphyly among species and have been unable to disentangle these taxa due to a lack of data and/or incomplete sampling of the genus. As a result, the interspecific relationships among Speyeria remain unresolved. In an attempt to achieve phylogenetic resolution of the genus, we conducted population genomic and phylogenomic analyses of all North American Speyeria species, as well as several subspecies, based on genome wide markers using the SbfI restriction enzyme and restriction site associated DNA sequencing (RADseq). Together, our analyses recovered 16 species within Speyeria, validating previous taxonomic work. However, consistent with recent molecular analyses, internal relationships have poor support. This lack of resolution indicates Speyeria represent an ongoing adaptive radiation, with incomplete lineage sorting, hybridization, and lack of postzygotic reproductive barriers, supporting this hypothesis.

Pages

62

Recommended Citation

Thompson, Erin. (2019). Phylogenomic analyses clarify butterfly species within the genus Speyeria despite evidence of a recent adaptive radiation. University of the Pacific, Thesis. https://scholarlycommons.pacific.edu/uop_etds/3583