From a single common ancestor, a plethora of lineages have evolved to inhabit our planet.  Through evolutionary time, some of these have flourished while others floundered.  Many have long gone extinct, whereas a few are undergoing extraordinary radiations on Earth today. My research aims to uncover the diversity of life around us, as well as the patterns and macroevolutionary processes that underlie diversification.  My focus is on vascular plants, the bulk of which are now—but were not always—angiosperms.

The rise of flowering plants, beginning in the Cretaceous period and resulting in more than 250,000 living species, is often portrayed as coincident with a dramatic drop in the diversity and abundance of other vascular plant lineages.  This has led to the prevailing view that all of these non-flowering plant groups—together comprising fewer than 14,000 extant species—simply succumbed to the ecological predominance of angiosperms.  However, the ultimate effects of flowering plant diversification were not equal among the remaining lineages; certain groups have been more successful than others in our angiosperm-dominated world.  Some, such as ginkgophytes or horsetails, have only a handful of living species.  Others, including clubmosses, conifers, and cycads, have up to several hundred. Leptosporangiate ferns, with perhaps as many as 11,000 extant species inhabiting a wide range of ecological niches, are truly the exception.

My current research program centers on the evolution and diversification of leptosporangiate ferns. Much of my inquiry is systematic in nature, emphasizing species delimitation and the identification of phylogenetic relationships within this group.  However, I have been increasingly interested in exploring links between fern and flowering plant radiations, and I am currently working to better resolve the origin of the modern tropical rain forest biome within which most leptosporangiate ferns reside.  In the future, I will continue integrating field work, morphological and molecular data, and phylogenetic approaches to further elucidate the evolutionary history of leptosporangiate ferns and other vascular plant lineages.