Written by Elof Axel Carlson, author of Genes, Radiation, and Society: The Life and Work of H.J. Muller (Ithaca: Cornell University Press, 1981), 2016.

Hermann Joseph Muller (1890-1967) was a geneticist who is best remembered for receiving a Nobel Prize in 1946 for his work in the field of radiation genetics, which he founded. Muller joined the faculty of Indiana University in 1945 and he retired in 1964. In his career he published more than 300 professional articles on genetics. He was born and raised in New York City, a third generation American. He attended Columbia University on a scholarship and joined the laboratory of T. H. Morgan for his PhD research. As a member of what is called “the fly lab,” he helped contribute to the establishment of classical genetics. Morgan, Muller, A. H. Sturtevant, and C. B. Bridges were the major participants in this approach. Their work provided the genetic basis for the evolution of life by natural selection. Muller focused on mutation and the gene. He identified the gene as the basis of life because all other components of the cell and organism are derived from the actions of genes. Muller argued that the first life was gene-like, a molecule that had the capacity to copy itself and its newly arising variations. He worked out the first mutation rates and showed they could vary in the same species. He showed that any gene carefully studied could be modified in its expression by other genes (called modifiers) or by changes in the environment, such as temperature. All of these findings Muller worked out by 1925. In 1926 he designed a special genetic stock to detect a category of mutations that kill embryos in early development. They are called recessive lethals. Muller devised a special stock, called ClB, which detected both recessive lethal mutations and newly arising recessive visible mutations. He found these in abundance and published his findings in 1927. This launched the field of radiation genetics.

Muller was concerned about how genetics was used and misused by society. He rejected the eugenics movement of his contemporaries because it was based on racism, elitism, sexism, and the false belief that most social failures are due to defective innate constitutions rather than to poor environments created by neglect, exploitation, illiteracy, and lack of opportunities. He denounced the rise of Nazi ideology as a racist perversion of genetics. In the Soviet Union he fought against a movement, Lysenkoism, that denied genes played a role in agricultural productivity, new varieties of foods, or in human development. Instead, Lysenkoists believed they could “shatter” heredity and retrain it to human needs. Muller debated Lysenko in Moscow in 1936 and called him a charlatan. By that time, Stalin, who was a supporter of Lysenkoism, had begun to “purge” those who disagreed with him. Muller barely escaped with his life from the USSR. He served as a volunteer in the Spanish Civil War, enlisting in the Canadian Blood Unit where he worked with Dr. Norman Bethune (1937). After leaving Spain, he worked in Edinburgh for three years and began a campaign for radiation protection. He and his students worked out the genetic mechanism by which x-rayed sperm lead to aborted embryos from the eggs they fertilized. Muller also applied this interpretation for radiation burns, tumor regression, and radiation sickness.

On his return to the United States he taught at Amherst College in Massachusetts and then was recruited to Indiana University by President Wells and Fernandus Payne. Muller had a flourishing program with numerous graduate students in his laboratory. He became a chief critic of those who ignored exposure to radiation. He was also a realist and felt the US should test its nuclear weapons to amass an arsenal for its protection during the Cold War. When the testing on both sides became a health risk, he urged a ban on nuclear testing in the air or sea.

Muller believed that people should have the right to choose the genes they want for their children through adoption, artificial insemination, donor eggs, or other technologies. He called this germinal choice. He warned that relaxation of natural selection would lead over the centuries to an increasing load of mutations that would weaken our health. He argued that we cannot exempt ourselves from nature and have to find ways to compensate for newly arising mutations.

Muller engaged in public debates and told his students they would encounter such situations in their own careers because governments often use “wishful thinking” to ignore or deny the reality of scientific findings. Many scientists try to avoid such debates, but Muller confronted them and felt a democracy is better served by debate than silence.

See also NAS Biographical Memoir of Hermann Joseph Muller, 1964 Retirement Tribute, IU Lilly Library Muller Collection