Lynn Margulis (born
Lynn Petra Alexander;
[1][2] March 5, 1938 – November 22, 2011)
[3] was an American
biologist best known for her scientific theory on the origin of
complex cells, called
symbiogenesis. She obtained a
bachelor degree from the
University of Chicago at age 19, and married
Carl Sagan, then a physics student. She graduated with
master's degree in genetics and zoology from the University of Chicago at age 22. While working for a PhD at the
University of California, Berkeley, she landed an appointment as lecturer at
Brandeis University, where she worked during 1964-1966. She received her PhD in 1965. She joined the faculty of
Boston University in 1966. In 1988 she became Distinguished Professor of Botany, and in 1997, Distinguished Professor of Geosciences at the
University of Massachusetts at Amherst.
[4]
Margulis conceived her theory on endosymbiosis when she was a junior faculty at Boston University. Her landmark publication, "On the Origin of Mitosing Cells" came out in 1967, after it was rejected by about fifteen journals. Ignored for a decade, her theory that
cell organelles such as
mitochondria and
chloroplasts were once independent
bacteria became widely accepted after it was substantiated by genetic evidences. She expanded her idea that
symbiosis is one of the major driving forces of evolution. Her theory also made her a proponent of
Gaia hypothesis, based on an idea developed by the English
environmental scientist James Lovelock. She was also the principal defender of the
five kingdom classification of
Robert Whittaker.
Variously branded as "Science's Unruly Earth Mother",
[5] a "vindicated heretic",
[6] or a scientific "rebel",
[7] Margulis was a strong critic of
Charles Darwin's
gradual selection theory and
modern evolutionary theory. She explicitly stated that she was a
Darwinist, but not a
neo-Darwinist, a position that sparked a lifelong debate with leading Darwinian biologists, including
Richard Dawkins,
George C. Williams, and
John Maynard Smith.
[8][9]
Margulis was member of the US
National Academy of Sciences from 1983. For her scientific innovations, President
Bill Clinton presented her the
National Medal of Science in 1999. The
Linnean Society of London awarded her the
Darwin-Wallace Medal in 2008.
Biography
Lynn Margulis was born in
Chicago, to Morris Alexander and Leona Wise Alexander. She was the eldest of four daughters. Her father was an attorney and run a company that made road paints. Her mother operated a travel agency.
[10] She entered the
Hyde Park Academy High School in 1952,
[11] describing herself as a bad student who frequently had to stand in the corner. She recalled that as early as the fourth grade to she was able to "tell bullshit from ... real authentic experience".
[2] A precocious child, she was accepted at the
University of Chicago Laboratory Schools[12] while on her second secondary year at the age of fifteen (she had applied a year earlier).
[13][14] She recalled, "because I wanted to go and they let me in".
[15] She entered the university after a year in 1954, and received her 12th grade certificate after being a college student in 1955.
[16] In 1957, at age 19, she earned a BA in
Liberal Arts. She joined the
University of Wisconsin to study biology under
Hans Ris and Walter Plaut, her supervisor, and graduated in 1960 with an
MS in genetics and zoology. (Her first publication was with Plaut, on the genetics of
Euglena, published in 1958 in the
Journal of Protozoology.)
[17] She then pursued research at the
University of California, Berkeley, under the zoologist Max Alfert. Before she could complete her dissertation, she was offered research associateship, and then lecturership, at
Brandeis University in Massachusetts in 1964. It was while working there that she obtained her PhD from the University of California, Berkeley in 1965. Her thesis was
An Unusual Pattern of Thymidine Incorporation in Euglena
.[16] In 1966 she moved to
Boston University, where she taught biology for twenty-two years. She was initially an Adjunct Assistant Professor, and appointed to Assistant Professor in 1967. She was promoted to Associate Professor in 1971, to full Professor in 1977, and to University Professor in 1986. In 1988 she was appointed Distinguished Professor of Botany at the
University of Massachusetts at Amherst. She was Distinguished Professor of Biology in 1993. In 1997 she transferred to the Department of Geosciences at Amherst to became Distinguished Professor of Geosciences "with great delight",
[18] the post which she held until her death.
[19]
Personal life
Margulis married astronomer
Carl Sagan in 1957 soon after she got her bachelor degree. Sagan was then a graduate student in physics at the University of Chicago. Their marriage ended in 1964, just before she completed her PhD. They had two sons
Dorion Sagan, who later became popular science writer and her collaborator, and
Jeremy Sagan, software developer and founder of
Sagan Technology.
In 1967, she married Thomas N. Margulis, a
crystallographer. They had a son Zachary Margulis-Ohnuma, New York City criminal defense lawyer, and a daughter
Jennifer Margulis, teacher and author .
[20][21] They divorced in 1980. She commented, "I quit my job as a wife twice," and, "it’s not humanly possible to be a good wife, a good mother and a first-class scientist. No one can do it — something has to go."
[22] In the 2000s she had a relationship with fellow biologist Ricardo Guerrero.
[11]
She was an
agnostic,
[11] and a staunch
evolutionist. But she totally rejected the
modern evolutionary synthesis,
[23] and said:
I remember waking up one day with an epiphanous revelation: I am not a neo-Darwinist! It recalled an earlier experience, when I realized that I wasn't a humanistic Jew.
Although I greatly admire Darwin's contributions and agree with most of his theoretical analysis and I am a Darwinist, I am not a neo-Darwinist.[9]
Her sister Joan Alexander married Nobel Laureate
Sheldon Lee Glashow; another sister, Sharon, married mathematician
Daniel Kleitman.
Death
Margulis died on November 22, 2011 at home in
Amherst,
Massachusetts, five days after suffering a
hemorrhagic stroke.
[1][2][22][24] As her wish, she was cremated and her ashes were scattered in her favorite research areas, near her home.
[25]
Contributions
Endosymbiosis theory
In 1966, as a young faculty member at
Boston University, Margulis wrote a theoretical paper titled "On the Origin of Mitosing Cells".
[26] The paper however was "rejected by about fifteen scientific journals," she recalled.
[27] It was finally accepted by
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
Ivan Wallin (1920) in the early-20th century, her 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). 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 fact that mitochondria descended from bacteria and chloroplasts from cyanobacteria was experimentally demonstrated in 1978 by Robert Schwartz and Margaret Dayhoff.
[28] This became the first proof of her theory.
[2]
The underlying theme of endosymbiosis theory, as formulated in 1966, was interdependence and cooperative existence of multiple
prokaryotic organisms; one organism phagocytosed 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 endosymbiosis 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 endosymbiosis 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.
[29]
In 1995, English 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.[30] |
” |
Symbiosis as evolutionary force
Margulis 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.
She also held a negative view of certain interpretations of
Neo-Darwinism that she felt were excessively focused on inter-organismic competition, as she believed that history will ultimately judge them as comprising "a minor twentieth-century religious sect within the sprawling religious persuasion of Anglo-Saxon Biology."
[31] She also believed 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 in a complete funk."
[31]
She opposed such competition-oriented views of evolution, stressing the importance of symbiotic or cooperative relationships between species.
Gaia hypothesis
Gaia hypothesis states that the Earth is a unit of organism, with all the different organisms in it merely its parts.
[32][33] It was formulated as a scientific hypothesis by an English scientist
James Lovelock in 1965, and publicized it in 1972. In a scientific perspective the hypothesis states that the Earth's environmental and geological conditions are maintained in stable and self-regulating process (
homeostasis) by its living organisms.
[34] Margulis joined forces with Lovelock, and strengthened the hypothesis with her expertise in microbiology. She described the Earth as "super organismic system" and its organisms interact and evolve through
cooperation.
[35][36] It was generally received with criticism, as it lacks testable evidence. But some scientists are of the opinion that it has a broader perspective and even might be tested in the future.
[37][38] Margulis was not in favour of the strong Gaia hypothesis of Lovelock, which has elements of
paganism.
[39] Her arguments are entirely biological, and inherently anti-Darwinian that it is cooperation that creates species, but not natural selection.
[9][35] But later supporters of the hypothesis embraced that the hypothesis is of Darwinian principle, and that the stabilizing effect (feedback mechanism) is promoted by natural selection on each organism.
[40][41][42] In 1991, an evolutionary biologist
John Maynard Smith had cautiously remarked:
| “ |
Every science needs Lynn Margulis... I think she is often wrong, but... she's wrong in such fruitful ways. I'm sure she's mistaken about Gaia, too. But I must say, she was crashingly right once, but many of us thought she was wrong then, too.[5][17] |
” |
AIDS/HIV theory
In 2009 Margulis co-authored with seven others a paper stating "Detailed research that correlates life histories of symbiotic spirochetes to changes in the immune system of associated vertebrates is sorely needed" and urging the "reinvestigation of the natural history of mammalian, tick-borne, and venereal transmission of spirochetes in relation to impairment of the human immune system."
[43] Margulis later argued that "there's no evidence that HIV is an infectious virus" and that AIDS symptoms "overlap ... completely" with those of
syphilis.
[44] Seth Kalichman, HIV researcher and professor of psychology who spent a year infiltrating HIV denialist groups, cited her 2009 paper as an example of
AIDS denialism "flourishing",
[45] and argued that her "endorsement of HIV/AIDS denialism defies understanding."
Metamorphosis theory
In 2009, via a then-standard publication-process known as "communicated submission", she was instrumental in getting the
Proceedings of the National Academy of Sciences (
PNAS) to publish a paper by
Donald I. Williamson rejecting "the Darwinian assumption that larvae and their adults evolved from a single common ancestor."
[46][47] Williamson's paper provoked immediate response from the
scientific community, including a countering paper in
PNAS.
[46] Conrad Labandeira of the
Smithsonian National Museum of Natural History said, "If I was reviewing [Williamson's paper] I would probably opt to reject it," he says, "but I'm not saying it's a bad thing that this is published.
What it may do is broaden the discussion on how metamorphosis works and…[on]…the origin of these very radical life cycles." But
Duke University insect developmental biologist Fred Nijhout said that the paper was better suited for the "
National Enquirer than the National Academy."
[48] In September it was announced that
PNAS would eliminate communicated submissions in July 2010.
PNAS stated that the decision had nothing to do with the Williamson controversy.
[47]
Five kingdoms of life
The entire life on earth was traditionally classified into
five kingdoms, as introduced by
Robert Whittaker in 1969.
[49] Margulis became the most important supporter, as well as critic.
[50] Critic in the sense that she was the first to recognize the limitations of Whittaker's classification of microbes.
[51] But later discoveries of new organisms, such as
archaea, and emergence of molecular taxonomy challenged the concept.
[52] By the mid-2000s, most scientists began to agree that there are more than five kingdoms.
[53][54] Margulis became the most important defender of the five kingdom classification. She rejected the
three-domain system introduced by
Carl Woese in 1990, which gained wide acceptance. She introduced an improved classification by which all life forms, including the newly discovered, could be integrated into the classical five kingdoms. According to her the main problem, archaea, falls under the kingdom Prokaryotae alongside bacteria (in contrast to the three-domain system which treat archaea as a higher taxon than kingdom, or the six-kingdom system which holds that it is a separate kingdom).
[52] Her concept is given in detail in her book
Five Kingdoms, written with Karlene V. Schwartz.
[55] It is mainly because of her that this five-kingdom system survives.
[18]
Awards and recognitions
- Elected Fellow of the American Association for the Advancement of Science in 1975.[16]
- Guggenheim Fellowship in 1978.[19]
- Elected to the National Academy of Sciences in 1983.
- Guest Hagey Lecturer, University of Waterloo, 1985[56]
- Inducted into the World of Art and Science,[57] the Russian Academy of Natural Sciences, and the American Academy of Arts and Sciences.[58]
- Miescher-Ishida Prize in 1986.[19]
- 1989, conferred the Commandeur de l’Ordre des Palmes Académiques de France.[16]
- Has her papers permanently archived in the Library of Congress, Washington, DC.
- 1992, recipient of Chancellor's Medal for Distinguished Faculty of the University of Massachusetts at Amherst.[18]
- 1995, elected Fellow of the World Academy of Art and Science.[59]
- 1998, recipient of the Distinguished Service Award of the American Institute of Biological Sciences.[18]
- 1998, elected Fellow of the American Academy of Arts and Sciences.
- 1999, recipient of the William Procter Prize for Scientific Achievement.
- 1999, recipient of the National Medal of Science, awarded by President William J. Clinton.
- 2002-2005, Alexander von Humboldt Prize.
- 2005, elected President of Sigma Xi, The Scientific Research Society.[59]
- Profiled in Visionaries: The 20th Century's 100 Most Important Inspirational Leaders, published in 2007.
- Founded Sciencewriters Books in 2006 with her son Dorion.[60]
- Was one of thirteen recipients in 2008 of the Darwin-Wallace Medal, heretofore bestowed every 50 years, by the Linnean Society of London.
- 2009, speaker at the Biological Evolution Facts and Theories Conference, held at the Pontifical Gregorian University, Rome aimed at promoting dialogue between evolutionary biology and Christianity.
- 2010, inductee into the Leonardo da Vinci Society of Thinking[61] at the University of Advancing Technology in Tempe, Arizona.
- 2010, NASA Public Service Award for Astrobiology.[19]
- 2012, Lynn Margulis Symposium: Celebrating a Life in Science, University of Massachusetts, Amherst, March 23–25, 2012
- Honorary doctorate from 15 universities.[59]
Select publications and bibliography
Books
- Margulis, Lynn (2009). "Genome acquisition in horizontal gene transfer: symbiogenesis and macromolecular sequence analysis". In Gogarten, Maria Boekels; Gogarten, Johann Peter; Olendzenski, Lorraine C. Horizontal Gene Transfer:Genomes in Flux 532. Humana Press. pp. 181–191. doi:10.1007/978-1-60327-853-9_10. ISBN 978-1-60327-852-2. PMID 19271185.
- 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 Dorion Sagan (1997). What Is Sex?, Simon and Schuster, 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 Margulis, Lynn (1993). The Garden of Microbial Delights: A Practical Guide to the Subvisible World, Kendall/Hunt, ISBN 0-8403-8529-3
- 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 (1991). "Symbiosis in Evolution: Origins of Cell Motility". In Osawa, Syozo; Honzo, Tasuku. Evolution of Life: Fossils, Molecules and Culture. Japan: Springer. pp. 305–324. doi:10.1007/978-4-431-68302-5_19. ISBN 978-4-431-68304-9.
- 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
Journals
- Guerrero, R; Margulis, L; Berlanga, M; Bandi, C; Macallister, J; Margulis, L (2013). "Symbiogenesis: the holobiont as a unit of evolution". International Microbiology 16 (3): 133–143. doi:10.2436/20.1501.01. PMID 24568029.
- Wier, AM; Sacchi, L; Dolan, MF; Bandi, C; Macallister, J; Margulis, L (2010). "Spirochete attachment ultrastructure: Implications for the origin and evolution of cilia". The Biological Bulletin 218 (1): 25–35. PMID 20203251.
- Brorson, O.; Brorson, S.-H.; Scythes, J.; MacAllister, J.; Wier, A.; Margulis, L. (2009). "Destruction of spirochete Borrelia burgdorferi round-body propagules (RBs) by the antibiotic Tigecycline". Proceedings of the National Academy of Sciences 106 (44): 18656–18661. doi:10.1073/pnas.0908236106. PMC 2774030. PMID 19843691. *
- Margulis, Lynn; Chapman, Michael; Dolan, Michael F. (2007). "Semes for analysis of evolution: de Duve's peroxisomes and Meyer's hydrogenases in the sulphurous Proterozoic eon". Nature Reviews Genetics 8 (10): 1. doi:10.1038/nrg2071-c1. PMID 17923858.
- Dolan, MF; Margulis, L (2007). "Advances in biology reveal truth about prokaryotes". Nature 445 (7123): 21. doi:10.1038/445021b. PMID 17203039.
- Margulis, L.; Chapman, M.; Guerrero, R.; Hall, J. (2006). "The last eukaryotic common ancestor (LECA): Acquisition of cytoskeletal motility from aerotolerant spirochetes in the Proterozoic Eon". Proceedings of the National Academy of Sciences 103 (35): 13080–13085. doi:10.1073/pnas.0604985103. PMC 1559756. PMID 16938841.
- Margulis, L.; Chapman, M.; Guerrero, R.; Hall, J. (2006). "The last eukaryotic common ancestor (LECA): Acquisition of cytoskeletal motility from aerotolerant spirochetes in the Proterozoic Eon". Proceedings of the National Academy of Sciences 103 (35): 13080–13085. doi:10.1073/pnas.0604985103. PMC 1559756. PMID 16938841.
- Margulis, L (2005). "Hans Ris (1914-2004). Genophore, chromosomes and the bacterial origin of chloroplasts". International Microbiology 8 (2): 145–8. PMID 16052465.
- Dolan, Michael F.; Melnitsky, Hannah; Margulis, Lynn; Kolnicki, Robin (2002). "Motility proteins and the origin of the nucleus". The Anatomical Record 268 (3): 290–301. doi:10.1002/ar.10161. PMID 12382325.
- Wier, A.; Dolan, M.; Grimaldi, D.; Guerrero, R.; Wagensberg, J.; Margulis, L. (2002). "Spirochete and protist symbionts of a termite (Mastotermes electrodominicus) in Miocene amber". Proceedings of the National Academy of Sciences 99 (3): 1410–1413. doi:10.1073/pnas.022643899. PMC 122204. PMID 11818534.
- Margulis, L.; Dolan, M. F.; Guerrero, R. (2000). "The chimeric eukaryote: Origin of the nucleus from the karyomastigont in amitochondriate protists". Proceedings of the National Academy of Sciences 97 (13): 6954–6959. doi:10.1073/pnas.97.13.6954. PMC 34369. PMID 10860956.
- Chapman, MJ; Margulis, L (1998). "Morphogenesis by symbiogenesis". International Microbiology 1 (4): 319–26. PMID 10943381.
- Margulis, L (1996). "Archaeal-eubacterial mergers in the origin of Eukarya: phylogenetic classification of life.". Proceedings of the National Academy of Sciences of the United States of America 93 (3): 1071–1076. PMC 40032. PMID 8577716.
- Margulis, L (1990). "Words as battle cries--symbiogenesis and the new field of endocytobiology". Bioscience 40 (9): 673–677. PMID 11541293.
- Lazcano, A; Guerrero, R; Margulis, L; Oró, J (1988). "The evolutionary transition from RNA to DNA in early cells.". Journal of Molecular Evolution 27 (4): 283–290. PMID 2464698.
- Bermudes, D; Margulis, L; Tzertzinis, G (1987). "Prokaryotic origin of undulipodia. Application of the panda principle to the centriole enigma". Annals of the New York Academy of Sciences 503: 187–197. doi:10.1111/j.1749-6632.1987.tb40608.x. PMID 3304075.
- Sagan, D; Margulis, L (1987). "Gaia and the evolution of machines.". Whole Earth Review 55: 15–21. PMID 11542102.
- Margulis, L; Bermudes, D (1985). "Symbiosis as a mechanism of evolution: status of cell symbiosis theory". Symbiosis 1: 101–124. PMID 11543608.
- Margulis, L (1980). "Undulipodia, flagella and cilia". Biosystems 12 (1-2): 105–108. PMID 7378551.
- Margulis, L (1976). "Genetic and evolutionary consequences of symbiosis". Experimental Parasitology 39 (2): 277–349. PMID 816668.
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