Assistant Scientist
Director of Conservation Genetic
Center for Conservation and Sustainable Development
Research Interests
• Conservation Genetics
• Quantitative Genetics
• Species-level molecular systematics
Evaluating species diversity and hybridization in North American Arisaema. Edwards is a population geneticist whose research includes studies of the genetic diversity of endangered species. The most recent treatment of North American Arisaema recognizes only two species: A. triphyllum and A. dracontium, yet both exhibit a very large amount of intraspecific morphological variation. Much of the variation, especially in the “triphyllum complex” has been previously attributed to rampant hybridization, for which there is little to no evidence. However, a recent study of the group involving examination of herbarium specimens (including critical collections made during two never-published doctoral studies), field observations of the species, recent data reported by contributors to iNaturalist, and critical examination of the literature proposed that at least nine North American species of Arisaema should be recognized. Within the “triphyllum complex,” six species were proposed: A. triphyllum, A. pusillum, A. stewardsonii, A. quinatum, A. acuminatum, and “A. sp. nov. A”, all of which are diploid with n = 28 except for A. triphyllum, which is a tetraploid with n = 56. Within the “dracontium complex,” three species were proposed: A. dracontium, A. macrospathum, and “A. sp. nov. B.” In this project, the student will conduct DNA sequencing using a 2b-rad-seq approach of samples of each of these morphologically distinct groups sampled from across their geographic ranges, reconstruct the phylogeny of the group, and analyze whether admixture occurs among the proposed species in the group. The goals of the study will be to evaluate: 1) whether the proposed species are genetically distinct, 2) whether they hybridize, and 3) the implications for conservation.