McClintock, Barbara (1902-1992), a United States geneticist. She won the Nobel Prize in physiology or medicine in 1983 for her discovery that certain genes in corn can move from one position to another along the length of a chromosome, causing genetic mutations. Many scientists had scoffed at her findings (first announced in 1951) because they ran contrary to the accepted theory that genes occurred at specific sites on chromosomes and were not able to move. Her research marked the beginning of modern molecular genetics.
McClintock was born in Hartford, Connecticut. She entered Cornell University's Agriculture School in 1919, and earned a doctorate in plant genetics in 1927. McClintock held several faculty positions at Cornell and other universities in the 1920's and 1930's before joining the staff of the Carnegie Institute of Washington genetics laboratory at Cold Spring Harbor, on Long Island, in 1942.