Thomas Hunt Morgan

Thomas Hunt Morgan was an American evolutionary biologist and embryologist whose laboratory work transformed Gregor Mendel's abstract laws of inheritance into physical, chromosomal biology. Born into an illustrious Kentucky family, Morgan earned his doctorate at Johns Hopkins before becoming professor of experimental zoology at Columbia University in New York.

In Columbia's legendary cramped 'Fly Room' (Room 613), Morgan and his brilliant students Alfred Sturtevant, Calvin Bridges, and Hermann Muller began breeding the common fruit fly, Drosophila melanogaster. In 1910, Morgan identified a single mutant male fly with white eyes instead of normal red eyes. By tracking its inheritance across generations, Morgan demonstrated that the gene for white eyes was located exclusively on the female X chromosome, providing the world's first proof of sex-linked inheritance. His laboratory mapped genes to linear loci along chromosomes and discovered genetic crossing over. In 1933, Morgan was awarded the Nobel Prize in Physiology or Medicine—the first geneticist ever so recognized.