|Richard E. Lenski is an evolutionary biologist who watches evolution unfold in a laboratory. The Hannah Distinguished Professor of Microbial Ecology at Michigan State University, he is internationally acclaimed for research focusing on ecological processes and genetic mechanisms that cause evolutionary change. He studies microorganisms in order to take advantage of their rapid generations and large populations, which makes it feasible to test evolutionary hypotheses by direct experimentation, and has examined 20,000 generations of E.coli bacteria to trace their adaptation to specific environments. He also looks at the evolution of artificial life in the form of self-replicating computer programs that mutate at random, compete, and evolve to perform complex functions. A graduate of Oberlin College, where he was elected to Phi Beta Kappa, Dr. Lenski earned a Ph.D. in zoology at the University of North Carolina in 1982. After post-doctoral research in zoology at the University of Massachusetts, Amherst, and a semester as a visiting assistant professor of biological sciences at Dartmouth College, he joined the faculty of the University of California, Irvine, as an assistant professor of ecology and evolutionary biology in 1985 and was named an associate professor three years later. Dr. Lenski accepted his present chair at Michigan State in 1991. He has taught special courses and workshops at the University of California, Davis, at the University of Basel and the University of Fribourg in Switzerland, and at the University of Alaska. In 1995, he served as vice-chair of the Gordon Research Conference on Population Biology and Evolution of Microbes and their Accessory Elements, and two years later he was co-chair of the National Research Conference on Ecology and Evolution of Infectious Diseases. A member of Sigma Xi, the honorary scientific society, he has been the recipient of an American Society of Naturalists Presidents Award, a National Science Foundation Presidential Young Investigator Award, a Guggenheim Fellowship, and a John D. and Catherine T. MacArthur Foundation Fellowship. He is a former visiting fellow of All Souls College, Oxford, and a fellow of the American Academy of Microbiology, and the American Academy of Arts and Sciences. A former associate editor of both Theoretical Population Biology and Evolution, Dr. Lenski formerly served on the editorial boards of Microbial Ecology and of the American Naturalist, on the editorial advisory board of Molecular Ecology, and as area editor of the Oxford University Press Encyclopedia of Evolution. He is the author or co-author of some 150 papers published in leading scientific journals.