born Oct. 22, 1903, Wahoo, Neb., U.S.
died June 9, 1989, Pomona, Calif.
U.S. geneticist.
He earned his Ph.D. from Cornell University. While studying Drosophila , he realized that genes must influence heredity chemically and designed a complex technique to determine the nature of those effects, showing that something as apparently simple as eye colour results from a long series of chemical reactions, which are affected by genes. With Edward L. Tatum , he found that the total environment of a bread mold could be varied so that researchers could locate and identify mutations relatively easily, concluding that each gene determines the structure of a specific enzyme, which in turn allows a single chemical reaction to proceed. For the "one gene, one enzyme" concept, they shared a 1958 Nobel Prize with Joshua Lederberg . Beadle later served as president of the University of Chicago (196068).