Lynn Margulis

Lynn Margulis (born Lynn Petra Alexander; March 5, 1938 – December 22, 2011) was an American evolutionary biologist, and was the primary modern proponent for the significance of symbiosis in evolution.

Historian Jan Sapp has said that "Lynn Margulis's name is as synonymous with symbiosis as Charles Darwin's is with evolution."

In particular, Margulis transformed and fundamentally framed current understanding of the evolution of cells with nuclei – an event Ernst Mayr called "perhaps the most important and dramatic event in the history of life" – by proposing it to have been the result of symbiotic mergers of bacteria.

She entered the Hyde Park Academy High School in 1952, describing herself as a bad student who frequently had to stand in the corner.

A precocious child, she was accepted at the University of Chicago Laboratory Schools at the age of fifteen.

In 1957, at age 19, she earned a BA from the University of Chicago in Liberal Arts.

Margulis married astronomer Carl Sagan in 1957 soon after she got her bachelor's degree.

Sagan was then a graduate student in physics at the University of Chicago.

(Her first publication, published with Plaut in 1958 in the Journal of Protozoology, was on the genetics of Euglena, flagellates which have features of both animals and plants.) She then pursued research at the University of California, Berkeley, under the zoologist Max Alfert.

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.

Before she could complete her dissertation, she was offered research associateship and then lectureship at Brandeis University in Massachusetts in 1964.

Their marriage ended in 1964, just before she completed her PhD. They had two sons, Dorion Sagan, who later became a popular science writer and her collaborator, and Jeremy Sagan, software developer and founder of Sagan Technology.

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. In 1966 she moved to Boston University, where she taught biology for twenty-two years.

Throughout her career, Margulis' work could arouse intense objection (one grant application elicited the response, "Your research is crap. Don't ever bother to apply again.") and her formative paper, "On the Origin of Mitosing Cells", appeared in 1967 after being rejected by about fifteen journals.

Still a junior faculty member at Boston University at the time, her theory that cell organelles such as mitochondria and chloroplasts were once independent bacteria was largely ignored for another decade, becoming widely accepted only after it was powerfully substantiated through genetic evidence.

She was initially an Adjunct Assistant Professor, then was appointed to Assistant Professor in 1967.

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 daughter Jennifer Margulis, teacher and author.

She was promoted to Associate Professor in 1971, to full Professor in 1977, and to University Professor in 1986.

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."

Margulis was elected a member of the US National Academy of Sciences in 1983.

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 UMass Amherst to become Distinguished Professor of Geosciences "with great delight", the post which she held until her death.

President Bill Clinton presented her the National Medal of Science in 1999.

In the 2000s she had a relationship with fellow biologist Ricardo Guerrero.

In 2002, Discover magazine recognized Margulis as one of the 50 most important women in science.

Margulis was also the co-developer of the Gaia hypothesis with the British chemist James Lovelock, proposing that the Earth functions as a single self-regulating system, and was the principal defender and promulgator of the five-kingdom classification of Robert Whittaker.

The Linnean Society of London awarded her the Darwin-Wallace Medal in 2008.

Called "science's unruly earth mother", a "vindicated heretic", or a scientific "rebel", Margulis was a strong critic of neo-Darwinism.

Her position sparked lifelong debate with leading neo-Darwinian biologists, including Richard Dawkins, George C. Williams, and John Maynard Smith.

Margulis' work on symbiosis and her endosymbiotic theory had important predecessors, going back to the mid-19th century – notably Andreas Franz Wilhelm Schimper, Konstantin Mereschkowski, Boris Kozo-Polyansky, and Ivan Wallin – and 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 her death.

Many of her major works, particularly those intended for a general readership, were collaboratively written with her son Dorion Sagan (whose father was Carl Sagan).

Margulis was born in Chicago, to a Jewish, Zionist family.

Her parents were Morris Alexander and Leona Wise Alexander.

She was the eldest of four daughters.

Her father was an attorney who also ran a company that made road paints.

Her mother operated a travel agency.