June 16, 2010
The year BARBARA MCCLINTOCK (1902–1992) was born, chromosomes had only just been linked to the proper development of embryos; the discovery that they comprised collections of the paired heritable traits first identified by Gregor Mendel and later called “genes” was a dozen years off. When McClintock began her own research, DNA had not yet been described and understood as the molecular basis of the genome. Her techniques were little different from those used by Mendel a century earlier: she bred plants and observed their changes over generations. Mendel had tended the humble, monastic pea; McClintock studied maize — counting the kernels, attending to the descent of mosaic and mixed pigments, peering through her microscope to discern the shifting loci. What this ancient grain taught her about genetics is both essential and haunting: certain genes, she found, actually transpose themselves from chromosome to chromosome, moving around the genome. Such movement causes dangerous, unstable mutations, but also allows cells to specialize, giving rise to the tissues and systems of multicellular life. To McClintock’s fellow biologists, genes seemed like the services in a kind of book of common prayer, bound together in an inherited liturgy followed inflexibly over the life of the cell. McClintock’s idea, which she termed transposition, suggested that a chromatic, improvisational genius was at work in the genome. Many of her colleagues could not accept a theory so estranged from received ideas, leading her to stop publishing on the topic for decades. When the brilliance of her science was later acknowledged, she received a Nobel Prize in 1983 — thirty-five years after her signal discovery. She laid bare the history of America’s dominant domestic crop, unlocked the secrets of disease processes, and helped open a new perspective on genetics — this view of life ever more entangled and complex, reaching from grandeur to grandeur.
ALSO BORN THIS DATE: Stan Laurel
Each day, HILOBROW pays tribute to one of our favorite high-, low-, no-, or hilobrow heroes on that person’s birthday.
READ MORE about members of the Hardboiled generation (1894-1903).