Sallie (Penny) Chisholm is Lee and Geraldine Martin Professor of Environmental Studies in the departments of civil and environmental engineering and biology at the Massachusetts Institute of Technology. She earned her Ph.D. in biology from SUNY Albany in 1974. Her research focuses on the ecology, evolution and comparative genomics of marine cyanobacteria and the viruses that infect them; Iron and phytoplankton growth; and ocean fertility. Internet: http://chisholmlab.mit.edu/people/chisholm.html