Margulis, Lynn

▪ 2001

      At a White House ceremony on March 14, 2000, Pres. Bill Clinton presented the U.S. National Medal of Science to eminent microbiologist Lynn Margulis, one of 12 distinguished recipients. She was cited “for her outstanding contributions to understanding of the development, structure, and evolution of living things, for inspiring new research in the biological, climatological, geological and planetary sciences, and for her extraordinary abilities as a teacher and communicator of science to the public.”

      Margulis was born in Chicago on March 5, 1938. Intellectually precocious, she graduated with an A.B. from the University of Chicago in 1957. She earned her M.S. in zoology and genetics from the University of Wisconsin at Madison in 1960 and her Ph.D. in genetics from the University of California, Berkeley, in 1965. She joined the biology department of Boston University in 1966 and taught there until 1988, when she was named distinguished university professor in the department of botany at the University of Massachusetts at Amherst. She retained that title when her affiliation at the university changed to the department of biology in 1993 and then to the department of geosciences in 1997.

      Throughout most of her career, Margulis was considered a radical by peers who pursued traditional Darwinian “survival of the fittest” approaches to biology. Her ideas, which focused on symbiosis—a living arrangement of two different organisms in an association that can be beneficial or unfavourable—were frequently greeted with skepticism and even hostility. Among her most important work was the development of the serial endosymbiotic theory of the origin of cells, which posits that eukaryotic cells (cells with nuclei) evolved from the symbiotic merger of nonnucleated bacteria that had previously existed independently. In this theory mitochondria and chloroplasts, two major organelles of eukaryotic cells, are descendants of once free-living bacterial species. She explained the concept in her first book, Origin of Eukaryotic Cells (1970). At the time, her theory was regarded as far-fetched, but it has since been widely accepted. She elaborated in her 1981 classic, Symbiosis in Cell Evolution (second edition, 1993), proposing that another symbiotic merger of cells with bacteria—this time spirochetes, a type of bacterium that undulates rapidly—developed into the internal transportation system of the nucleated cell. This hypothesis, which also met with much professional resistance, remained the subject of much of Margulis's research work into 2000.

      Another area of interest for Margulis was her long collaboration with British scientist James Lovelock on the controversial Gaia hypothesis. This proposes that the Earth can be viewed as a single self-regulating organism—that is, a complex entity whose living and inorganic elements are interdependent and whose life-forms actively modify the environment to maintain hospitable conditions.

      Margulis was elected to the National Academy of Sciences in 1983 and was one of three American members of the Russian Academy of Natural Sciences. She held honorary doctorates from several universities and was awarded the William Procter Prize of Sigma Xi, the international research society, in 1999. Margulis was the author of several popular books on science (many co-written with her son Dorion Sagan), as well as more than 130 other technical works.

Amy R. Tao

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