Muller, << MUHL uhr, >> Hermann Joseph (1890-1967), was an American geneticist. By exposing fruit flies to X rays, Muller proved that X rays can produce mutations (sudden changes in genes). The results of this work, published in 1927, brought him the 1946 Nobel Prize for physiology or medicine.
Muller was born in New York City. He began his research on heredity with Thomas Hunt Morgan while a student at Columbia University. They studied the linkage of genes and the crossing over of chromosome strands that occur during genetic recombination, a process that takes place just before cells divide. Muller became a professor of zoology at Indiana University in 1945.
