Dr. Lewis received the B.A. degree from the University of Minnesota in 1939 and the Ph.D. from the California Institute of Technology in 1942. He served to the rank of captain in the United States Army Air Force from 1942-1945 as a meteorologist and oceanographer in the Pacific Theater. He joined the Caltech faculty in 1946 as an instructor. In 1956 he was appointed Professor of Biology and in 1966 Thomas Hunt Morgan Professor of Biology. He was a Rockefeller Foundation Fellow at Cambridge University, England (1947-48) and Guest Professor at the Institute of Genetics, University of Copenhagen, Denmark (1975-76).

He is a member of the National Academy of Sciences, the Genetics Society of America, the American Philosophical Society, and the American Academy of Arts and Sciences. He is a foreign member of the Royal Society (London) and an honorary member of the Genetical Society of Great Britain. He is a recipient of the Thomas Hunt Morgan Medal (1983), the Gairdner Foundation International award (1987), the Wolf Foundation prize in medicine (1989), the Rosenstiel award (1990), the National Medal of Science (1990), the Albert Lasker Basic Medical Research Award (1991), and the Louisa Gross Horwitz prize (1992). He holds honorary degrees from the University of Umea, Umea, Sweden (1981) and the University of Minnesota (1993).

Dr. Lewis and his wife, Pamela, an artist, have three children: Hugh, an attorney who lives in Bellingham, Washington, Glenn (deceased) and Keith, a biology research assistant who lives in Berkeley, California.