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Lynn Margulis

Lynn Margulis (born March 5, 1938) is an American biologist and University Professor in the Department of Geosciences at the University of Massachusetts Amherst.[1] She is best known for her theory on the origin of eukaryotic organelles, and her contributions to the endosymbiotic theory—which is now generally accepted for how certain organelles were formed.


Endosymbiotic theory

Lynn Margulis attended the University of Chicago as an undergraduate, earned a master's degree from the University of Wisconsin-Madison in 1960, and received her Ph.D. in 1963 from UC Berkeley. In 1966, as a young faculty member at Boston University, she wrote a theoretical paper entitled The Origin of Mitosing Eukaryotic Cells.[2] The paper however was "rejected by about fifteen scientific journals," Margulis recalled.[3] It was finally accepted by The Journal of Theoretical Biology and is considered today a landmark in modern endosymbiotic theory. Although it draws heavily on symbiosis ideas first put forward by mid-19th century scientists and by Merezhkovsky (1905) and Wallin (1920) in the early-20th century, Margulis's endosymbiotic theory formulation is the first to rely on direct microbiological observations (as opposed to paleontological or zoological observations which were previously the norm for new works in evolutionary biology). The paper was initially heavily rejected, as symbiosis theories had been dismissed by mainstream biology at the time. Weathering constant criticism of her ideas for decades, Margulis is famous for her tenacity in pushing her theory forward, despite the opposition she faced at the time.

The underlying theme of endosymbiotic theory, as formulated in 1966, was interdependence and cooperative existence of multiple prokaryotic organisms; one organism engulfed another, yet both survived and eventually evolved over millions of years into eukaryotic cells. Her 1970 book, Origin of Eukaryotic Cells, discusses her early work pertaining to this organelle genesis theory in detail. Currently, her endosymbiotic theory is recognized as the key method by which some organelles have arisen (see endosymbiotic theory for a discussion) and is widely accepted by mainstream scientists. The endosymbiotic theory of organogenesis gained strong support in the 1980s, when the genetic material of mitochondria and chloroplasts was found to be different from that of the symbiont's nuclear DNA.[4]

In 1995, prominent evolutionary biologist Richard Dawkins had this to say about Lynn Margulis and her work:
“ I greatly admire Lynn Margulis's sheer courage and stamina in sticking by the endosymbiosis theory, and carrying it through from being an unorthodoxy to an orthodoxy. I'm referring to the theory that the eukaryotic cell is a symbiotic union of primitive prokaryotic cells. This is one of the great achievements of twentieth-century evolutionary biology, and I greatly admire her for it.[5] ”

Theory of symbiotic relationships driving evolution

She later formulated a theory to explain how symbiotic relationships between organisms of often different phyla or kingdoms are the driving force of evolution. Genetic variation is proposed to occur mainly as a result of transfer of nuclear information between bacterial cells or viruses and eukaryotic cells. While her organelle genesis ideas are widely accepted, symbiotic relationships as a current method of introducing genetic variation is something of a fringe idea. However, examination of the results from the Human Genome Project lends some credence to an endosymbiotic theory of evolution[citation needed]—or at the very least Margulis's endosymbiotic theory is the catalyst for current ideas about the composition of the human genome[citation needed]. Significant portions of the human genome are either bacterial or viral in origin—some clearly ancient insertions, while others are more recent in origin. This strongly supports the idea of symbiotic—and more likely parasitic—relationships being a driving force for genetic change in humans, and likely all organisms[citation needed]. It should be noted that while the endosymbiotic theory has historically been juxtaposed to Neo-Darwinism as a competitor, the two theories are not irreconcilable. An emerging synthesis holds that natural selection works on many levels (genetic up to the ecosystem) and variation is introduced both at the genetic and the cellular level[citation needed].

She does, however, hold a negative view of certain interpretations of Neo-Darwinism, excessively focused on inter-organismic competition, as she believes that history will ultimately judge them as comprising "a minor twentieth-century religious sect within the sprawling religious persuasion of Anglo-Saxon Biology."[6] She also believes that proponents of the standard theory "wallow in their zoological, capitalistic, competitive, cost-benefit interpretation of Darwin - having mistaken him... Neo-Darwinism, which insists on [the slow accrual of mutations by gene-level natural selection], is a complete funk."[6]

She opposes such competition-oriented views of evolution, stressing the importance of symbiotic or cooperative relationships between species.


In addition to rejecting Neo-Darwinian evolution as an explanation for diversity (on the grounds that speciation due solely to random mutation and differential survival has yet to be proven), Margulis holds a number of opinions outside of mainstream science. In 2009 she co-authored a paper [7] arguing that the change in spirochete form, from more motile helical to more inactive cyst and back, may be a causal contributor to AIDS. In 2009 she also pushed the journal Proceedings of the National Academy of Sciences (PNAS) to publish a paper by Donald I. Williamson arguing that butterflies are the result of hybridization of a now extinct insect and velvet worms[8][9]. As a member of the National Academy of Sciences, Margulis has the ability to "communicate" scientific papers, allowing them to be published with minimal review. Williamson's paper provoked immediate response from the scientific community, including a paper in PNAS [10]. Developmental Biologist and Professor at Duke university Fred Nijhout was quoted as saying that the paper was better suited for "National Enquirer than the National Academy.". In September it was announced that PNAS will eliminate Communicated submissions in July 2010 but PNAS stated that the decision had nothing to do with the Williamson controversy.[9]


* Margulis was elected to the National Academy of Sciences in 1983 and served as Chairman of the Academy’s Space Science Board Committee on Planetary Biology and Chemical Evolution.
* guest Hagey Lecturer, University of Waterloo, 1985 [4]
* She was inducted into the World Academy of Art and Science, the Russian Academy of Natural Sciences, and the American Academy of Arts and Sciences between 1995 and 1998.
* In 1998 the Library of Congress, Washington, DC, announced that it would permanently archive Dr. Margulis' papers.
* In 1999 she received the William Procter Prize for Scientific Achievement for scientific achievement.
* In 1999, she was awarded the National Medal of Science by President William J. Clinton.
* She is also a proponent and co-developer of the modern version of Gaia hypothesis, based on an idea developed by the English atmospheric scientist James Lovelock.
* She is profiled in a book published in 2006 by Resurgence Magazine in the UK, called Visionaries: The 20th Century's 100 Most Important Inspirational Leaders.
* In 2006 with her son Dorion, she founded Sciencewriters Books, an imprint of Chelsea Green Publishing for science books.
* In 2007 she expressed her support for a new investigation of the September 11, 2001 attacks.[11]
* In 2008 she was one of thirteen recipients of the Darwin-Wallace Medal, which, until now, has only been bestowed every 50 years, by the Linnean Society of London.
* In March 2009 she spoke at the Biological Evolution Facts and Theories Conference held at the Pontifical Gregorian University, Rome aimed at promoting dialogue between evolutionary biology and Christianity.
* In June 2010 she was inducted into the Leonardo DaVinci Society of Thinking[12][relevant? – discuss]; accepting induction at the University of Advancing Technology in Tempe, AZ.


She attended the University of Chicago at age 14 having entered 'because she wanted to go and they let me in' [13]

She married her first husband at age 19. She was the first wife of astronomer Carl Sagan, and is the mother of Dorion Sagan, popular science writer and co-author; Jeremy Sagan, software developer and founder of Sagan Technology; Zachary Margulis-Ohnuma, New York City criminal defense lawyer; and Jennifer Margulis, teacher and author.[citation needed]

See also

* Symbiogenesis

Select Publications and Bibliography

* Margulis, Lynn and Dorion Sagan, 2007, Dazzle Gradually: Reflections on the Nature of Nature, Sciencewriters Books, ISBN 978-1-933392-31-8
* Margulis, Lynn and Eduardo Punset, eds., 2007 Mind, Life and Universe: Conversations with Great Scientists of Our Time, Sciencewriters Books, ISBN 978-1-933392-61-5
* Margulis, Lynn, 2007, Luminous Fish: Tales of Science and Love, Sciencewriters Books, ISBN 978-1-933392-33-2
* Margulis, Lynn and Dorion Sagan, 2002, Acquiring Genomes: A Theory of the Origins of Species, Perseus Books Group, ISBN 0-465-04391-7
* Margulis, Lynn, et al., 2002, The Ice Chronicles: The Quest to Understand Global Climate Change, University of New Hampshire, ISBN 1-58465-062-1
* Margulis, Lynn, 1998, Symbiotic Planet : A New Look at Evolution, Basic Books, ISBN 0-465-07271-2
* Margulis, Lynn and Karlene V. Schwartz, 1997, Five Kingdoms: An Illustrated Guide to the Phyla of Life on Earth, W.H. Freeman & Company, ISBN 0-613-92338-3
* Margulis, Lynn and Dorian Sagan, 1997, What Is Sex?, Simon and Shuster, ISBN 0-684-82691-7
* Margulis, Lynn and Dorion Sagan, 1997, Slanted Truths: Essays on Gaia, Symbiosis, and Evolution, Copernicus Books, ISBN 0-387-94927-5
* Sagan, Dorion and Lynn Margulis, 1993, The Garden of Microbial Delights: A Practical Guide to the Subvisible World, Kendall/Hunt, ISBN 0840385293
* Margulis, Lynn, 1992, Symbiosis in Cell Evolution: Microbial Communities in the Archean and Proterozoic Eons, W.H. Freeman, ISBN 0-7167-7028-8
* Margulis, Lynn, ed, 1991, Symbiosis as a Source of Evolutionary Innovation: Speciation and Morphogenesis, The MIT Press, ISBN 0-262-13269-9
* Margulis, Lynn and Dorion Sagan, 1991, Mystery Dance: On the Evolution of Human Sexuality, Summit Books, ISBN 0-671-63341-4
* Margulis, Lynn and Dorion Sagan, 1987, Microcosmos: Four Billion Years of Evolution from Our Microbial Ancestors, HarperCollins, ISBN 0-04-570015-X
* Margulis, Lynn and Dorion Sagan, 1986, Origins of Sex : Three Billion Years of Genetic Recombination, Yale University Press, ISBN 0-300-03340-0
* Margulis, Lynn, 1982, Early Life, Science Books International, ISBN 0-86720-005-7
* Margulis, Lynn, 1970, Origin of Eukaryotic Cells, Yale University Press, ISBN 0-300-01353-1


1. ^ Lynn Margulis biography at U. Mass. (Accessed July 15, 2006)
2. ^ Lynn Sagan (1967). "On the origin of mitosing cells". J Theor Bio. 14 (3): 255–274. doi:10.1016/0022-5193(67)90079-3. PMID 11541392.
3. ^ John Brockman, The Third Culture, New York: Touchstone, 1995, 135.
4. ^ Acceptance Doesn't Come Easy (Accessed July 15, 2006)
5. ^ John Brockman, The Third Culture, New York: Touchstone, 1995, 144.
6. ^ a b Mann, C. (1991) "Lynn Margulis: Science's Unruly Earth Mother," Science, 252, 378-381
7. ^ [1] Spirochete round bodies. Syphilis, Lyme disease & AIDS: Resurgence of “the great imitator”?, SYMBIOSIS Vol. 47, No. 1 (2009), pp. 51-58
8. ^ [2] Caterpillars evolved from onychophorans by hybridogenesis, PNAS (2009)
9. ^ a b [3] Controversial caterpillar-evolution study formally rebutted, Scientific American Online
10. ^ http://www.pnas.org/content/early/2009/10/22/0910229106] Caterpillars did not evolve from onychophorans by hybridogenesis, PNAS (2009)
11. ^ UMass scientist a 9/11 doubter, Kristin Palpini, The Daily Hampshire Gazette, 9/11/07
12. ^ (http://davincithinking.org/inductees.html)
13. ^ BBC Radio 4 "A Life With...(Series 5) - A life with Microbes, Broadcast 16 July 2009"

* Interview and portrait of Lynn Margulis by Ariane Laroux in Portraits Parlés, éditions l'Age d'Homme (2006)

External links

* UMass Bio Dept. (Accessed July 22, 2008)
* UMass Geo Dept. (Accessed March 3, 2005)
* www.immaculata.edu (Accessed March 3, 2005)
* San Jose Science, Technology and Society, 2004-2005 Linus Pauling Memorial Lectures (Accessed March 3, 2005)
* The Endosymbiotic Theory (Accessed March 3, 2005)
* Gaia Is a Tough Bitch
* Audio interview with Margulis
* Interview with Lynn Margulis on Gaia 5 minute MP3 from October 2005

Biology Encyclopedia

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