Department of Integrative Biology
Ph.D. Comprehensive Exam

Audrey Spencer
Ph.D Student
Drs. Ackerfield & Bruederle’s lab, Denver Botanic Gardens

When: Oct. 24, 2023 at 11:00a
Where: SI 4127

Systematics and Biogeography of the Eastern Asian-North American Disjunct Genus, Physocarpus (Rosaceae)

My dissertation research uses Physocarpus, a genus of shrubs in the rose family, to address questions related to the evolutionary and biogeographic histories of vascular plants. I will use restriction site-associated DNA sequencing to investigate the systematics of Physocarpus based on a geographically and taxonomically representative sampling schema. I also intend to clarify the taxonomy of Physocarpus by considering morphological and molecular evidence in an integrative taxonomy framework. Next, I will construct a fossil-calibrated time tree (where branch lengths are correlated with time) to explore the order and timing of divergence within the genus as well as its biogeographical history. Finally, I will investigate the phylogeographic factors contributing to the contemporary intracontinental disjunction of Physocarpus intermedius, including the potential role of glacial refugia.