Which geneticist was the first woman to win the National Medal of Science?

Barbara McClintock was the first woman to receive the United States National Medal of Science, in 1970.

McClintock was a pioneering cytogeneticist who studied maize chromosomes. Her experiments led her to identify transposable elements, DNA sequences that can move within a genome and alter gene activity. She called them controlling elements.

Her ideas were initially received skeptically because the prevailing view treated genes as fixed positions. Later molecular biology confirmed that mobile genetic elements are widespread in organisms, and her work gained broad recognition.

McClintock received the 1983 Nobel Prize in Physiology or Medicine for her discovery of transposable genetic elements. The National Medal of Science honor came earlier, in 1970, and marked a major US recognition of her research.