Barbara McClintock (June 16, 1902 – September 2, 1992) was an American scientist and one of the world's most distinguished
cytogeneticists. After receiving her PhD in botany from
Cornell University in 1927, McClintock began studying
chromosomes and how they change during reproduction in maize. She developed the technique for visualizing maize chromosomes and used microscopic analysis to demonstrate many fundamental genetic ideas. One of these was the notion of
genetic recombination by
crossing over during
meiosis – a mechanism by which chromosomes exchange information. McClintock produced the first
genetic map for maize, linking regions of the chromosome to physical traits. She also demonstrated the role of the
telomere and the
centromere, regions of the chromosome that are important in the conservation of
genetic information. Recognized as among the best in the field, she received the 1983
Nobel Prize in Physiology or Medicine.
This 1947 photograph, in the collection of the Smithsonian Institution Archives, shows McClintock in her laboratory at the Cold Spring Harbor Laboratory in Laurel Hollow, New York.Photograph credit: Science Service, Smithsonian Institution; restored by Adam Cuerden