Dr. Barbara McClintock was a pioneer in the field of cytogenetics, the study of chromosomes. After earning her doctorate at Cornell, she continued her studies on the cytogenetics of maize at Cold Spring Harbor Laboratory. Dr. McClintock discovered that genes could “jump” within chromosomes, therefore switching certain physical traits on and off. She announced her findings on genetic transposition in 1951, but since her discovery strayed from the prevailing genetic theory, her work was largely ignored by the scientific community until the 1960s. In 1983, she was awarded the Nobel Prize in Physiology or Medicine. In addition to genetic transposition, she proposed the idea of epigenetics — the study of changes in phenotype without altering the DNA sequence itself — almost 40 years before the field was established.