Director of Conservation Genetics
Center for Conservation and Sustainable Development
• Conservation Genetics
• Quantitative Genetics
• Species-level molecular systematics
Conservation genetics of the federally endangered Physaria globosa. Edwards is a population geneticist whose research includes studies of the genetic diversity of endangered species. Short’s bladderpod (Physaria globosa; Brassicaceae) is a federally endangered, biennial/perennial plant species with insect-pollinated flowers and gravity or water-dispersed seeds. The distribution of the species is discontinuous, with populations occupying four disjunct locations: north-central KY (Bluegrass region), the extreme southwestern tip of IN (Shawnee Hills region), and two discontinuous areas (Central Basin and Highland Rim regions) in central TN. A recent analysis of P. globosa showed that only 31 populations of the species remain, and of these, 23 had fewer than 100 individuals. Given the small size and isolation of some populations, it is possible that they may have experienced reductions in genetic diversity due to genetic bottlenecks or drift, which may affect the long-term resilience of populations. However, genetic diversity has not been measured previously in populations of P. globosa, such that it is unknown whether populations have experienced reductions in their levels of genetic diversity. In this study, the REU student will conduct a genetic analysis of populations of P. globosa from throughout its geographic range using genetic data from 20 microsatellite loci. Specifically, the REU student will analyze the microsatellite data to understand: 1) rangewide patterns of genetic diversity and structure in P. globosa and how genetic structure is affected by the disjunctions in the species range, 2) levels of genetic diversity in P. globosa and whether populations show evidence of having experienced declines in genetic diversity as the result of genetic bottlenecks or genetic drift, and 3) implications for prioritization of in-situ and ex-situ conservation efforts for the species.