Joined W&L Faculty in 1976
Graduate Degrees: M.S., University of Maryland
Ph.D., Virginia Polytechnic Institute and State University
I am collaborating with a W&L colleague, molecular biologist, Dr. Maryanne Simurda, who is sequencing ITS regions of the nuclear DNA in an effort to determine the evolutionary history of H. virginicum in relation to its closest relatives. The final stage of this study has revealed that H. virginicum is a monophyletic taxon, distinct from other similar Helenium species, and that it has a remarkable disjunct distribution between Virginia and Missouri. We have found that the sister group to H. virginicum is a cluster of H. autumnale populations that grow on the Bruce Peninsula, Ontario, Canada.
In 2001 I began a long-term experiment in collaboration with colleagues (Drs. Hurd, and Hamilton) to study the question of whether decreasing the diversity of plant species living together in a community decreases resistance of that community to invasion. This is an important question today, at a time when alien species are seen as a threat to native species, and when the rate of species extinction is high, and so we are trying to understand the ramifications of these losses. The work is being carried out at a research site on campus where 66 plots each 3 m X 3 m in area have been sown with native plant species at three levels of diversity (3, 12, and 24 species). Over 15 years we shall be monitoring plots for evidence of differences in resistance to invasion, and seeking an understanding of the mechanisms responsible through the study of three trophic levels.
Evolution Seminar (Biology 295)
Biological Diversity (Biology 246)
Plant Diversity (Biology 235)
Evolution (Biology 340)