George Wells Beadle (October 22, 1903 - June 9, 1989) was an American scientist in the field of genetics. He shared half of the 1958 Nobel Prize in Physiology or Medicine with Edward Lawrie Tatum for their discovery that genes act by regulating biochemical events within the cell. The other half of that year's award went to Joshua Lederberg.
Beadle and Tatum's key experiments involved exposing the bread mold Neurospora crassa to x-rays, causing mutations. In a series of experiments, they showed that these mutations caused changes in specific enzymes involved in metabolic pathways. These experiments led them to propose a direct link between genes and enzymatic reactions, known as the "one gene, one enzyme" hypothesis.
Beadle was born in Wahoo, Nebraska. He received his Bachelor of Science degree from the University of Nebraska in 1928. He received his Ph.D. from Cornell University in 1931. Beadle worked with 1933 Nobel Prize winner Thomas Hunt Morgan at the California Institute of Technology. He was a professor at Harvard University and Caltech. He also served as president of the University of Chicago from 1961-1968. He published his book The Language of Life in 1966.