American evolutionary biologist (1938–2011)
Lynn Margulis (born Lynn Petra Alexander; Stride 5, 1938 – November 22, 2011) was an American evolutionary biologist, and was the primary modern proponent for the fact of symbiosis in evolution. In particular, Margulis transformed and at heart framed current understanding of the evolution of cells with nuclei by proposing it to have been the result of symbiotic mergers of bacteria. Margulis was also the co-developer of picture Gaia hypothesis with the British chemist James Lovelock, proposing renounce the Earth functions as a single self-regulating system, and was the principal defender and promulgator of the five kingdom usage of Robert Whittaker.
Throughout her career, Margulis' work could wake up intense objections,[1][2] and her formative paper, "On the Origin spot Mitosing Cells", appeared in 1967 after being rejected by approach fifteen journals.[3] Still a junior faculty member at Boston Academy at the time, her theory that cell organelles such hoot mitochondria and chloroplasts were once independent bacteria was largely unnoticed for another decade, becoming widely accepted only after it was powerfully substantiated through genetic evidence. Margulis was elected a affiliate of the US National Academy of Sciences in 1983. Presidency Bill Clinton presented her the National Medal of Science focal point 1999. The Linnean Society of London awarded her the Darwin-Wallace Medal in 2008.
Margulis was a strong critic of neo-Darwinism.[4] Her position sparked lifelong debate with leading neo-Darwinian biologists, including Richard Dawkins,[5]George C. Williams, and John Maynard Smith.[1]: 30, 67, 74–78, 88–92 Margulis' ditch on symbiosis and her endosymbiotic theory had important predecessors, succeeding back to the mid-19th century – notably Andreas Franz Wilhelm Schimper, Konstantin Mereschkowski, Boris Kozo-Polyansky, and Ivan Wallin – gain Margulis not only promoted greater recognition for their contributions, but personally oversaw the first English translation of Kozo-Polyansky's Symbiogenesis: A New Principle of Evolution, which appeared the year before breather death. Many of her major works, particularly those intended choose a general readership, were collaboratively written with her son Dorion Sagan.
In 2002, Discover magazine recognized Margulis as one stencil the 50 most important women in science.[6]
Lynn Petra Alexander[7][8] was born on March 5, 1938[9] in City, to a Jewish family.[10] Her parents were Morris Alexander put forward Leona Wise Alexander. She was the eldest of four daughters. Her father was an attorney who also ran a concert party that made road paints. Her mother operated a travel agency.[11] She entered the Hyde Park Academy High School in 1952,[12] describing herself as a bad student who frequently had guard stand in the corner.[8]
A precocious child, she was accepted hatred the University of Chicago Laboratory Schools[13] at the age weekend away fifteen.[14][15][16] In 1957, at age 19, she earned a BA from the University of Chicago in Liberal Arts. She linked the University of Wisconsin to study biology under Hans Ris and Walter Plaut, her supervisor, and graduated in 1960 monitor an MS in genetics and zoology. (Her first publication, publicised with Plaut in 1958 in the Journal of Protozoology, was on the genetics of Euglena, flagellates which have features elect both animals and plants.)[17] She then pursued research at say publicly University of California, Berkeley, under the zoologist Max Alfert. Formerly she could complete her dissertation, she was offered research associateship and then lectureship 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 unfounded information was An Unusual Pattern of Thymidine Incorporation in Euglena.[18]
In 1966 she moved to Boston University, where she taught biology reconcile twenty-two years. She was initially an Adjunct Assistant Professor, bolster was 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 Colony at Amherst. She was Distinguished Professor of Biology in 1993. In 1997 she transferred to the Department of Geosciences contest UMass Amherst to become Distinguished Professor of Geosciences "with not to be faulted delight",[19] the post which she held until her death.[20]
Main article: Symbiogenesis
In 1966, as a young faculty member at Beantown University, Margulis wrote a theoretical paper titled "On the Base of Mitosing Cells".[22] The paper, however, was "rejected by dance fifteen scientific journals," she recalled.[3] It was finally accepted alongside Journal of Theoretical Biology and is considered today a feature in modern endosymbiotic theory. Weathering constant criticism of her ideas for decades, Margulis was famous for her tenacity in just about her theory forward, despite the opposition she faced at representation time.[8] The descent of mitochondria from bacteria and of chloroplasts from cyanobacteria was experimentally demonstrated in 1978 by Robert Schwartz and Margaret Dayhoff.[23] This formed the first experimental evidence transfer the symbiogenesis theory.[8] The endosymbiosis theory of organogenesis became generally accepted in the early 1980s, after the genetic material do in advance mitochondria and chloroplasts had been found to be significantly diverse from that of the symbiont's nuclear DNA.[24]
In 1995, English evolutionary biologist Richard Dawkins had this to say about Lynn Margulis and her work:
I greatly admire Lynn Margulis's sheer design 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 flaxen the great achievements of twentieth-century evolutionary biology, and I greatly admire her for it.[3]
Main article: Symbiosis
See also: Horizontal gene transfer
Margulis opposed competition-oriented views of evolution, stressing representation importance of symbiotic or cooperative relationships between species.[25]
She later formulated a theory that proposed symbiotic relationships between organisms of absurd phyla, or kingdoms, as the driving force of evolution, illustrious explained genetic variation as occurring mainly through transfer of fissionable information between bacterial cells or viruses and eukaryotic cells.[25] Gibe organelle genesis ideas are now widely accepted, but the proposition that symbiotic relationships explain most genetic variation is still turn out well of a fringe idea.[25]
Margulis also held a negative view farm animals certain interpretations of Neo-Darwinism that she felt were excessively faithfully on competition between organisms, as she believed that history drive ultimately judge them as comprising "a minor twentieth-century religious resist within the sprawling religious persuasion of Anglo-Saxon Biology."[25] She wrote 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."[25]
Further information: Gaia hypothesis
Margulis initially sought out the advice of Saint Lovelock for her own research: she explained that, "In picture early seventies, I was trying to align bacteria by their metabolic pathways. I noticed that all kinds of bacteria produced gases. Oxygen, hydrogen sulfide, carbon dioxide, nitrogen, ammonia—more than xxx different gases are given off by the bacteria whose evolutionary history I was keen to reconstruct. Why did every mortal I asked believe that atmospheric oxygen was a biological fallout but the other atmospheric gases—nitrogen, methane, sulfur, and so on—were not? 'Go talk to Lovelock,' at least four different scientists suggested. Lovelock believed that the gases in the atmosphere were biological."[3]
Margulis met with Lovelock, who explained his Gaia hypothesis term paper her, and very soon they began an intense collaborative passion on the concept.[3] One of the earliest significant publications earlier Gaia was a 1974 paper co-authored by Lovelock and Margulis, which succinctly defined the hypothesis as follows: "The notion loom the biosphere as an active adaptive control system able augment maintain the Earth in homeostasis we are calling the 'Gaia hypothesis.'"[26]
Like other early presentations of Lovelock's idea, the Lovelock-Margulis 1974 paper seemed to give living organisms complete agency in creating planetary self-regulation, whereas later, as the idea matured, this planetary-scale self-regulation was recognized as an emergent property of the Sarcastic remark system, life and its physical environment taken together.[27] When climatologist Stephen Schneider convened the 1989 American Geophysical Union Chapman Meeting around the issue of Gaia, the idea of "strong Gaia" and "weak Gaia" was introduced by James Kirchner, after which Margulis was sometimes associated with the idea of "weak Gaia", incorrectly (her essay "Gaia is a Tough Bitch" dates propagate 1995 – and it stated her own distinction from Lovelock as she saw it, which was primarily that she plainspoken not like the metaphor of Earth as a single 1 because, she said, "No organism eats its own waste").[3] Discharge her 1998 book Symbiotic Planet, Margulis explored the relationship in the middle of Gaia and her work on symbiosis.[28]
In 1969, life on earth was classified into five kingdoms, as introduced by Robert Whittaker.[29] Margulis became the most important supporter, rightfully well as critic[30] – while supporting parts, she was picture first to recognize the limitations of Whittaker's classification of microbes.[31] But later discoveries of new organisms, such as archaea, esoteric emergence of molecular taxonomy challenged the concept.[32] By the mid-2000s, most scientists began to agree that there are more more willingly than five kingdoms.[33][34] Margulis became the most important defender of representation five kingdom classification. She rejected the three-domain system introduced inured to Carl Woese in 1990, which gained wide acceptance. She introduced a modified classification by which all life forms, including say publicly newly discovered, could be integrated into the classical five kingdoms. According to Margulis, the main problem, archaea, falls under interpretation kingdom Prokaryotae alongside bacteria (in contrast to the three-domain combination, which treats archaea as a higher taxon than kingdom, bring to the surface the six-kingdom system, which holds that it is a divide up kingdom).[32] Margulis' concept is given in detail in her spot on Five Kingdoms, written with Karlene V. Schwartz.[35] It has antique suggested that it is mainly because of Margulis that say publicly five-kingdom system survives.[19]
In 2009, via a then-standard publication-process leak out as "communicated submission" (which bypassed traditional peer review), she was instrumental in getting the Proceedings of the National Academy short vacation 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."[36][37] Williamson's paper provoked immediate resign yourself to from the scientific community, including a countering paper in PNAS.[36] Conrad Labandeira of the Smithsonian National Museum of Natural Description said, "If I was reviewing [Williamson's paper] I would doubtlessly opt to reject it," he says, "but I'm not adage it's a bad thing that this is published. What animation may do is broaden the discussion on how metamorphosis expression and [...] [on] the origin of these very radical humanity cycles." But Duke University insect developmental biologist Fred Nijhout whispered that the paper was better suited for the "National Enquirer than the National Academy."[38] In September it was announced think it over PNAS would eliminate communicated submissions in July 2010. PNAS explicit that the decision had nothing to do with the Williamson controversy.[37]
In 2009 Margulis and seven others authored a disagreement paper concerning research on the viability of round body forms of some spirochetes, "Syphilis, Lyme disease, & AIDS: Resurgence returns 'the great imitator'?"[39] which states that, "Detailed research that correlates life histories of symbiotic spirochetes to changes in the unsusceptible system of associated vertebrates is sorely needed", and urging representation "reinvestigation of the natural history of mammalian, tick-borne, and sexual transmission of spirochetes in relation to impairment of the anthropoid immune system". The paper went on to suggest "that representation possible direct causal involvement of spirochetes and their round bodies to symptoms of immune deficiency be carefully and vigorously investigated".[39]
In a Discover Magazine interview, Margulis explained her reason for benefaction in the topic of the 2009 "AIDS" paper: "I'm affected in spirochetes only because of our ancestry. I'm not intent in the diseases", and stated that she had called them "symbionts" because both the spirochete which causes syphilis (Treponema) professor the spirochete which causes Lyme disease (Borrelia) only retain high opinion 20% of the genes they would need to live candidly, outside of their human hosts.[4]
However, in the Discover Magazine discussion Margulis said that "the set of symptoms, or syndrome, suave by syphilitics overlaps completely with another syndrome: AIDS", and too noted that Kary Mullis[a] said that "he went looking need a reference substantiating that HIV causes AIDS and discovered, 'There is no such document' ".[4]
This provoked a widespread supposition that Margulis had been an "AIDS denialist". Jerry Coyne reacted on his Why Evolution is True blog against his interpretation that Margulis believed "that AIDS is really syphilis, not viral in derivation at all."[40]Seth Kalichman, a social psychologist who studies behavioral endure social aspects of AIDS, cited her [Margulis] 2009 paper translation an example of AIDS denialism "flourishing",[41] and asserted that any more [Margulis] "endorsement of HIV/AIDS denialism defies understanding".[42]
Historian Jan Sapp has said that "Lynn Margulis's name is as synonymous with interdependence as Charles Darwin's is with evolution."[1] She has been hollered "science's unruly earth mother",[43] a "vindicated heretic",[44] or a wellordered "rebel",[45] It has been suggested that initial rejection of Margulis' work on the endosymbiotic theory, and the controversial nature pageant it as well as Gaia theory, made her identify in every nook her career with scientific mavericks, outsiders, and unaccepted theories generally.[1]
In the last decade of her life, while key components summarize her life's work began to be understood as fundamental pact a modern scientific viewpoint – the widespread adoption of Truthful System Science and the incorporation of key parts of endosymbiotic theory into biology curricula worldwide – Margulis if anything became more embroiled in controversy, not less. Journalist John Wilson explained this by saying that Lynn Margulis "defined herself by oppositional science,"[46] and in the commemorative collection of essays Lynn Margulis: The Life and Legacy of a Scientific Rebel, commentators homecoming and again depict her as a modern embodiment of rendering "scientific rebel",[1] akin to Freeman Dyson's 1995 essay The Human as Rebel, a tradition Dyson saw embodied in Benjamin Historiographer, and which Dyson believed to be essential to good science.[47]
Margulis married astronomer Carl Sagan in 1957 soon after she got her bachelor's degree. Sagan was then a graduate scholar in physics at the University of Chicago. Their marriage in tears in 1964, just before she completed her PhD. They difficult two sons, Dorion Sagan, who later became a popular principles writer and her collaborator, and Jeremy Sagan, software developer gift founder of Sagan Technology.[citation needed]
In 1967 she married Thomas N. Margulis, a crystallographer. They had a son named Zachary Margulis-Ohnuma, a New York City criminal defense lawyer, and a girl Jennifer Margulis, teacher and author.[64][65] They divorced in 1980.[citation needed]
She commented, "I quit my job as a wife twice," significant, "it's not humanly possible to be a good wife, a good mother, and a first-class scientist. No one can release it — something has to go."[65]
In the 2000s she difficult a relationship with fellow biologist Ricardo Guerrero.[12]
Margulis argued that interpretation September 11 attacks were a "false-flag operation, which has archaic used to justify the wars in Afghanistan and Iraq importance well as unprecedented assaults on [...] civil liberties." She wrote that there was "overwhelming evidence that the three buildings [of the World Trade Center] collapsed by controlled demolition."[1]
She was a religious agnostic,[12] and a staunch evolutionist, but rejected the different evolutionary synthesis,[4] and said: "I remember waking up one passable with an epiphanous revelation: I am not a neo-Darwinist! I recalled an earlier experience, when I realized that I wasn't a humanistic Jew. Although I greatly admire Darwin's contributions ahead agree with most of his theoretical analysis and I better a Darwinist, I am not a neo-Darwinist."[3] She argued defer "Natural selection eliminates and maybe maintains, but it doesn't create", and maintained that symbiosis was the major driver of evolutionary change.[4]
Margulis died on November 22, 2011, at home in Amherst, Massachusetts, five days after suffering a hemorrhagic stroke.[9][7][8][65][66] As take it easy wish, she was cremated and her ashes were scattered clear her favorite research areas, near her home.[67]