George Beadle

George Wells Beadle was born October 22, 1903, an American geneticist who would spend years staring at fungus under controlled mutation. Working with Edward Tatum, he exposed the bread mold Neurospora crassa to x-rays, inducing mutations, then traced how each genetic break disrupted a specific enzyme in the cell's metabolic assembly line. The experiments were elegant and relentless: one mutation, one missing enzyme, one broken chemical step. In 1958 the work won him half the Nobel Prize in Physiology or Medicine for demonstrating that genes directly govern biochemical events inside cells - the "one gene-one enzyme hypothesis" that bridged genetics and biochemistry. He later served as president of the University of Chicago from 1961 to 1968. Beadle died June 9, 1989, decades after the mold experiments that turned inheritance into a readable chemical language.