Born 20 May 1918; died 21 Jul 2004 at age 86.
American developmental geneticist who was awarded the 1995 Nobel Prize for Physiology or Medicine for discovering the functions that control early embryonic development with co-winners Christiane Nüsslein-Volhard and Eric F. Wieschaus who identified and classified 15 key genes that determine the body plan and formation of body segments of the fruit fly Drosophila melanogaster. Lewis studied the next step, the homeotic genes that govern the development of a larval segment into a specific body segment. (Homeotic means that something has been changed into the likeness of something else.) Lewis found a co-linearity in time and space between the order of the genes in the bithorax complex and their effect regions in the segments.