Kirk R. Johnson is the Sant Director of the Smithsonian's National Museum of Natural History. He received his PhD in geology and paleobotany from Yale University in 1989, and did postdoctoral research in the rainforests of northern Australia before joining the Denver Museum of Natural History in 1991, where he directed the installation of the museum's Prehistoric Journey exhibit. His research focuses on fossil plants, the environmental effects of the dinosaur-smiting asteroid, and the birth and death of biomes. Johnson lives in Washington, D. C.