Thomas Hunt Morgan
Morgan, Thomas Hunt, 1866–1945, American zoologist, b. Lexington, Ky., Ph.D. Johns Hopkins, 1890. He was professor of experimental zoology at Columbia (1904–28) and from 1928 was director of the laboratory of biological sciences at the California Institute of Technology. He is noted for his ingenious demonstration of the physical basis of heredity and the importance of the gene, using in his research the fruit fly, Drosophila. He described the phenomena of linkage and crossing over, which he and his students utilized to map the linear arrangement of genes along the chromosome. Morgan received the 1933 Nobel Prize in Physiology or Medicine. His books, classics in the literature of genetics, include The Physical Basis of Heredity (1919), Mechanism of Mendelian Heredity (rev. ed. 1923), Evolution and Genetics (1925), The Theory of the Gene (rev. ed. 1928), and Embryology and Genetics (1934).