David M. Williams is a diatom systematist–taxonomist. His research is divided between empirical studies on the systematics and biogeography of diatoms and theoretical studies related to advances in systematic theory, especially as it relates to cladistics. In addition to his work on diatom phylogeny, systematics, and biogeography, he has focused on the role fossils have in determining evolutionary relationships in diatoms.Quentin D. Wheeler is an insect taxonomist, author, columnist, and podcaster. He was professor of entomology in Cornell University, Dean of the College of Liberal Arts and Sciences in Arizona State University, Keeper and Head of Entomology at the Natural History Museum in London, Director of the Division of Environmental Biology of the U.S. National Science Foundation, and President of the State University of New York College of Environmental Science and Forestry.