Research Summary:

I study the evolution of diatoms in the context of earth history. My taxonomic focus is the diatom family Thalassiosiraceae, a family of marine and freshwater diatoms. There appears to have been a major invasion from the marine to the freshwater environment about 20 million years ago. Subsequently, these diatoms have become a major component of lake ecosystems. They have undergone periodic extinctions and radiations, apparently coinciding with glacial cycles. My most active research project is the study of speciation in the genus Stephanodiscus since the last ice age. I and colleagues are combining molecular tools with morphological studies, physiological studies and paleontological studies to examine the evolution of diatom species in the context of climate-driven limnological change. Lastly, I once took a short, regrettable foray into the systematics of a so-called dinosaur which continues to draw attention to itself. I have a fully equipped DNA lab and share facilities with the lab of Dr. Bob Jansen. I also have outstanding light microscopic capability, full algal culturing facilities, and a well-curated personal diatom collection, especially focussing on neo- and paleo-lacustrine samples from across the USA. Students interested in diatom systematics, diatom ecology, theoretical and applied aquatic biology are encouraged to consider graduate training in my laboratory, as are students interested in using the properties of the diatom system (especially extensive fossil record, easy laboratory manipulation for experimentation) to address general questions about evolutionary and ecological principles.