Barbara McClintock was a cytogeneticist who discovered 'transposable elements,' or 'jumping genes.' While studying the inheritance patterns of maize (corn), she noticed that certain genes could move within and between chromosomes, turning other genes on or off. At the time, her findings challenged the established belief that genes were fixed in place on chromosomes like beads on a string. Her genius was so far ahead of its time that the scientific community largely ignored her work for decades. It wasn't until the 1970s, when molecular biology confirmed her theories, that she received widespread recognition. In 1983, she became the first woman to win an unshared Nobel Prize in Physiology or Medicine.