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Dr. Lynn Margulis (born March 15, 1938) is an American biologist and University Professor in the Department of Geosciences at the University of Massachusetts Amherst. 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.
Additional recommended knowledge
Lynn Margulis attended the University of Chicago as an undergraduate, 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. The paper however was "rejected by about fifteen scientific journals," Margulis recalled. 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.
In 1995, prominent Neo-Darwinist, evolutionary biologist Richard Dawkins had this to say about Lynn Margulis and her work:
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—or at the very least Margulis's endosymbiotic theory is the catalyst for current ideas about the composition of the human genome. 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. It should be noted that while the endosymbiotic theory has historically been juxtaposed with Neo-Darwinism, the two theories are not incompatible and the truth is likelier to be that natural selection works on many levels (genetic up to the ecosystem) and variation is introduced both at the genetic and the cellular level.
She does, however, hold a negative view of Neo-Darwinism, as she believes that history will ultimately judge the theory as "a minor twentieth-century religious sect within the sprawling religious persuasion of Anglo-Saxon Biology." 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), is a complete funk."
Margulis' present day efforts, in the form of books and lectures, strongly stress a symbiotic—and cooperative—relationship between all organisms and a strong leaning toward Gaia theory. Her advocacy outside the realm of biology and toward more sociopolitical ends has been criticized by more mainstream scientists—somewhat similar to criticisms aimed toward Carl Sagan's latter day ideas.
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.
Publications and bibliography
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lynn_Margulis". A list of authors is available in Wikipedia.|