Muller, Hermann Joseph (mŭl`ər), 1890–1967, American geneticist and educator, b. New York City, grad. Columbia (B.A., 1910; Ph.D., 1916). A student of 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
..... Click the link for more information. , he taught (1915–18) at Rice Institute, Tex., at Columbia (1918–20), and at the Univ. of Texas from 1920 until he became senior geneticist (1933–37) of the Institute of Genetics in Moscow. In 1945 he became professor of zoology at Indiana Univ. His method for recognizing spontaneous gene mutation mutation, in biology, a sudden, random change in a gene , or unit of hereditary material, that can alter an inheritable characteristic. Most mutations are not beneficial, since any change in the delicate balance of an organism having a high level of adaptation to its
..... Click the link for more information. led to his discovery of a technique for artificially inducing mutations by means of X rays that has since had broad theoretical and practical application. For this discovery he was awarded the 1946 Nobel Prize in Physiology or Medicine. His writings include Out of the Night (1935), Genetics, Medicine, and Man (1947; written with others), and Studies in Genetics (1962). He also wrote articles on the biological effects of atomic radiation.

Muller, Hermann Joseph

(born Dec. 21, 1890, New York, N.Y., U.S.—died April 5, 1967, Indianapolis, Ind.) U.S. geneticist. He attended Columbia University. The possibility of consciously guiding human evolution provided the initial motivation for his research, leading him to work in the Soviet Union's Institute of Genetics. He later assisted the Republican forces in the Spanish Civil War before returning to the U.S. in 1940; he thereafter taught principally at Indiana University (1945–67). In 1926 he first induced genetic mutations through the use of X rays, and he demonstrated that mutations are the result of breakages in chromosomes and of changes in individual genes. His receipt of the Nobel Prize in 1946 increased his opportunities to publicize the dangers posed by accumulating spontaneous mutations in the human gene pool as a result of industrial processes and radiation, and he devoted much energy to increasing public awareness of the genetic dangers of radiation.