American geneticist who studied the Neurospora red bread mold. By subjecting the mold to X-rays, he caused it to mutate. He then observed that some mold lost the ability to produce a particular organic compound in needed to survive. By adding different but similar compounds and seeing if the mold used it, he could unravel the chemical reactions by which the mold synthesized needed chemicals. Beadle concluded that the characteristic function of the gene was to control the synthesis of a particular enzyme. For this hypothesis, which he published with Tatum, he shared the 1958 Nobel prize in medicine with Tatum and Lederberg.

Lederberg, Tatum