Exhibition Visionary Female Researchers: Barbara McClintock

Barbara McClintock is born on 16 June 1902 in Hartford, Connecticut, the third of four children of physician Thomas Henry McClintock and pianist Sara Handy McClintock. From 1908 onwards, the family lives in Brooklyn, New York.

The inquisitive Barbara reads extensively and is unusually independent even as a child. Her parents do not support her desire to study, but after working as an employment agent after high school, she enrols at Cornell University in Ithaca, New York. Her interests are wide-ranging: in addition to studying botany, she also takes courses in meteorology and political science.

While still a student, McClintock begins conducting research in the new field of cytogenetics. She becomes an assistant to botanist Lowell Randolph, with whom she first describes a triploid maize plant with three complete sets of chromosomes in a single cell in 1926. After differences with Randolph, she moves to become an assistant to Lester W. Sharp, who allows her to conduct her research independently and becomes her doctoral supervisor.

McClintock receives her doctorate in 1927 with a thesis on triploid maize and spends the next few years working primarily with George Beadle, who later wins the Nobel Prize, and Marcus M. Rhoades. During these economically difficult years of the Great Depression, the three young scientists live on grants from the National Research Council.

In 1933, McClintock receives a scholarship from the Guggenheim Foundation to work with Curt Stern in Berlin. However, Stern soon moves to California because, as a Jewish scientist, he is subject to repression by the Nazi regime in Germany. Nevertheless, McClintock goes to Berlin as planned to work at the Kaiser Wilhelm Institute. However, she is so shocked by the political situation following the Nazis' seizure of power that the Guggenheim Foundation agrees to her early return to the United States.

McClintock returns to Cornell University. In 1936, on the initiative of Lewis Stadler, she is appointed assistant professor at the University of Missouri, where she studies chromosome breaks in maize caused by X-rays. Her observation that breaks can ‘heal’ under certain conditions proves to be groundbreaking for her later research.

On recommendation, she is offered a temporary position as director of the Department of Genetics at the Carnegie Institution in Cold Spring Harbor, which McClintock accepts. She has no teaching duties and can therefore devote herself entirely to her research. This position is soon converted to a permanent one, and McClintock continues her research in Cold Spring Harbor until the end of her life. In 1944, McClintock is inducted into the US National Academy of Sciences. In 1945, she becomes the first woman to serve as president of the Genetics Society of America.

McClintock begins her research, which would lead to the discovery of ‘jumping genes’ (transposons), in 1944. While her colleagues are firmly convinced that genes are firmly anchored in the genome, McClintock's experiments prove that genes can jump and that genetic material is influenced by the environment. However, it is not until the 1970s that Barbara McClintock's work on transposition begins to receive the attention it deserves. In 1983, she is awarded the Nobel Prize in Physiology and Medicine for her research. 

Barbara McClintock dies at the age of 90 on 2 September 1992 in New York.