Current research focuses on the origin and subsequent radiation of major groups of land plants and the developmental evolution of biological characters that define these clades. Much of our research is devoted to understanding the early evolution of flowering plants (Darwin's “abominable mystery”). These efforts are largely focused on the evolution of double fertilization and endosperm, two of the most important and defining features of flowering plants. Our analyses draw upon a variety of approaches from cell biology to developmental biology to the integration of inclusive fitness theory. Other areas of study include the origin of vascular plants (the evolution of water-conducting tissues) and the evolution of mycorrhizal associations in mycoheterotrophic land plants (plants that receive carbon from their fungal partners).