1909-1975

American geneticist who shared the Nobel Prize for Physiology or Medicine in 1958 with George Beadle and Joshua Lederberg for their work showing genetic transmission in bread molds. Using normal and mutated chromosomes, they demonstrated that specific genes are responsible for particular enzymes. This "one-gene-one-enzyme hypothesis" helped confirm his suspicion that all biochemical processes are genetically regulated. Because of this and other contributions to the field, Tatum is considered a founder of molecular genetics.