Lynn Margulis
"Environment Earth: Gaia's Past as Prologue"
Monday, January 14, 2002, 11:30 AM
Dr. Lynn Margulis has revolutionized the way we think about life on earth by revealing the deep and unexpected connections that link the planet and all living things into one organic system. Dr. Margulis overturned the historic three-kingdom classification of organisms, worked with Dr. James Lovelock to develop the Gaia Hypothesis, and first posited the endosymbiotic basis of cellular evolution.
Margulis is a Distinguished University Professor of Geosciences at the University of Massachusetts, Amherst. She was elected to the National Academy of Sciences in 1983, received from William J. Clinton the Presidential Medal of Science in 1999. The Library of Congress, Washington, D.C., announced in 1998 that it will permanently archive her papers. She was a faculty member at Boston University for 22 years.
Her publications, spanning a wide range of scientific topics, include original contributions to cell biology and microbial evolution. She is best known for her theory of symbiogenesis, which challenges a central tenet of neodarwinism. She argues that inherited variation, significant in evolution, does not come mainly from random mutations. Rather new tissues, organs, and even new species evolve primarily through the long-lasting intimacy of strangers. The fusion of genomes in symbioses followed by natural selection, she suggests, leads to increasingly complex levels of individuality. Dr. Margulis is also acknowledged for her contribution to James Lovelock's Gaia concept. Gaia theory posits that the Earth's surface interactions among living beings, sediment, air, and water have created a vast self-regulating system.
Professor Margulis, who participates in hands-on teaching activities at levels from middle to graduate school, is the author of many articles and books. The most recent include Symbiotic Planet: A New Look at Evolution (1998) and Acquiring Genomes: A Theory of the Origin of Species (2002), co-written with Dorion Sagan. Indeed, over the past decade and a half, Professor Margulis has co-written a number of books with Sagan, among them What is Sex? (1997), What is Life? (1995), Mystery Dance: On the Evolution of Human Sexuality (1991), Microcosmos: Four Billion Years of Evolution from Our Microbial Ancestors (1986), and Origins of Sex: Three Billion Years of Genetic Recombination (1986). Her work with K. V. Schwartz provides a consistent formal classification of all life on Earth and has led to the third edition of Five Kingdoms: An Illustrated Guide to the Phyla of Life on Earth (1998). Their evolutionary classification scheme was generated from scientific results of numerous colleagues. The logical basis for it is summarized in her single-authored book Symbiosis in Cell Evolution: Microbial Communities in the Archean and Proterozoic Eons (second edition, 1993). The bacterial origins of both chloroplasts and mitochondria are established. At present she works on the possible origin of cilia from spirochetes.
LECTURE SUMMARY
Currently a Distinguished University Professor of Geosciences at the University of Massachusetts, Amherst, Dr. Lynn Margulis plays down the scale of accomplishment which, against much opposition, she has achieved over the last few decades.
The Gaia Hypothesis was proposed by Dr. James Lovelock in collaboration with Dr. Margulis who has been Lovelock’s principal collaborator for twenty-five years.
There were two fundamental components of Lovelock and Margulis’s Gaia theory:
The planet is, in Margulis’s words, a “super organismic system.” Evolution is the result of cooperative, not competitive, processes.
The Theory of Endosymbiosis was first put forward by Margulis in the late 1960s, at the same time that the Gaia Hypothesis was first being stated. To summarize: primitive cells gained entry into host cells as undigested prey or as internal parasites after which the “arrangement” quickly became mutually beneficial to both partners. All plants and animals are descended from these first endosymbiotic cells.
Her paper describing this theory was rejected by over a dozen scientific journals because no one knew how to evaluate it. Finally, after a long and hard struggle against peer-reviewed resistance, she prevailed. And now, what was once regarded as an absurd speculation is taken as self-evident truth…as the most likely explanation of the origin and evolution of life on Earth.
The Five-kingdom classification of living organisms on planet earth, developed by Margulis, replaced the traditional plant kingdom/animal kingdom classification two decacdes ago. This did not please many of her peers at the time, and, as with Gaia and Endosymbiosis, it is now widely accepted.
“What is life?” Dr. Margulis may be the most qualified scientist in the world to answer this question. Her answer is characteristically iconoclastic:
“'What is life?' is a linguistic trap. To answer according to the rules of grammar, we must supply a noun, a thing. But life on Earth is more like a verb. It is a material process, surfing over matter like a slow wave. It is a controlled artistic chaos, a set of chemical reactions so staggeringly complex that more than 4 billion years ago it began a sojourn that now, in human form, composes love letters and uses silicon computers to calculate the temperature of matter at the birth of the universe.”
Dr. Margulis is Member of the National Academy of Science, obtaining her A.B., University of Chicago in 1957, an M.S. at the University of Wisconsin in 1960, Ph.D. at the University of California, Berkeley, in 1963.