Barbara McClintock was a pioneering American geneticist whose discovery of transposable or jumping genes in the 1940s baffled most of her contemporaries for nearly three decades. McClintock spent nearly fifty years working apart from the mainstream of the scientific community. Yet her colleagues had such a high regard for her as an adherent to rigid scientific principles that they accepted her discovery of transposable genes decades before others could confirm her observations. McClintock was eventually awarded the Nobel Prize in medicine or physiology in 1983 for this prescient discovery.

McClintock was born on June 16, 1902, in Hartford, Connecticut. After graduating from Erasmus High School in Brooklyn, McClintock enrolled at Cornell University in 1919. McClintock became interested in the study of the cells, known as cytology, under the tutelage of Lester Sharp, a professor who gave her private lessons on Saturdays. She was invited to take graduate-level genetics courses while still in...