Sturtevant, Alfred H.

Sturtevant, Alfred H. (Henry) (1891–1970) geneticist; born in Jacksonville, Ill. As a research assistant in Thomas H. Morgan's "fly room" at Columbia University (1915–28), he used the fruit fly Drosophila to determine that genes are arranged in linear order. His analysis of these "linkage groups" in reference to two other genes on the same chromosome (1913) became the classical method for chromosome mapping. He moved with Morgan to the California Institute of Technology (1928–62), where he remained an active lecturer and visiting professor after his retirement. Sturtevant's major contributions to genetics include the genetic role in sexual selection and development, and the importance of chromosomal "crossing over" in mutations. His research on lethal genes influenced his later writings on the effects of atomic bomb tests on human evolution. Having grown up on a farm, he also had a lifelong interest in animals, especially in the social insects.