Thomas Hunt Morgan (September 25, 1866 – December 4, 1945) was an American evolutionary biologist, geneticist, embryologist, and science author who won the Nobel Prize in Physiology or Medicine in 1933 for discoveries elucidating the role that the chromosome plays in heredity. During his distinguished career, Morgan wrote 22 books and 370 scientific papers. As a result of his work, Drosophila became a major model organism in contemporary genetics. The Division of Biology which he established at the California Institute of Technology has produced seven Nobel Prize winners.