Biodiversity Systematics
Understanding the microevolutionary processes that have shaped contemporary biodiversity patterns in amphibians and reptiles has been a core focus of my research. To achieve this I integrate multiple disciplines and approaches including genomics, ecology, population genetics, natural history, and bioinformatics. My work has revealed a wide spectrum of phylogeographic patterns across species and regions of secondary contact between previously isolated lineages, presenting a much more complex picture of the regions and species I have studied. These systems have also offered a rich comparative framework for studying landscape barriers to gene flow, complex patterns of genomic biodiversity, and the evolution of reproductive isolation and phenotypic divergence.
What causes mitonuclear discordance and how can we accurately delimit species in the face of it?
Mitonuclear discordance is a frequently encountered pattern in phylogeographic studies and occurs when mitochondrial and nuclear DNA display conflicting signals. Discordance among these genetic markers can be caused by several factors including confounded taxonomies, gene flow, and incomplete lineage sorting. My work used a case of mitonuclear discordance in a problematic complex of Central American toads to (1) investigate the causes of discordance, (2) test delimitation hypotheses and methods in the face of discordance, and (3) highlight the importance of using multiple marker types when evaluating species boundaries in cryptic species.
How can we reinforce unstable taxonomies and create genomic tools for conservation management?
In the face of anthropogenic change and an urgency to document and conserve biodiversity, accurate species delimitation and conservation management is of tantamount importance. My past collaborative work has focused on generating genomic resources to investigate the species boundaries of earless lizards of the genus Holbrookia. This has included generating (1) transcriptomic datasets to explore potentially adaptive loci and genetic divergence, and (2) genome-wide (ddRADseq) datasets to investigate and reinforce the taxonomy of H. lacerata and H. subcaudalis using a reference-based taxonomic approach.
Photos courtesy of Troy Hibbitts.
Other Projects
Under construction….