Lynn Margulis

 

Lynn Margulis (1938–2011) was an evolutionary biologist and author renowned for developing the serial endosymbiotic theory, an evolutionary theory that challenges Darwinism by proposing that eukaryotic cells evolved through a combination of symbiosis and natural selection.

Not only was Margulis a brilliant scientist, but she was also celebrated for her original ideas and her ability to make connections across different fields to explain complex concepts. She was a devoted mother of four children and a passionate advocate for women in science.

Margulis obtained a bachelor’s degree in Liberal Arts at the surprisingly young age of 18,  and she went on to earn a master’s degree in Genetics and Zoology from the University of Wisconsin and a PhD in Genetics from the University of California, Berkeley, in 1965. She taught for 22 years at Boston University before becoming a Professor of Geosciences at the University of Massachusetts Amherst in 1988, where she worked throughout the remainder of her life. 

Margulis' research career unfolded during a time when the role of DNA and genes in inheritance was the dominant focus in biology. Yet, she was unafraid to question established assumptions and was among the first to identify non-nuclear genes in plant cells—a discovery that challenged the belief that organisms are solely governed by genetic information in the cell nucleus. 

Her subsequent work led to the development of the ‘serial endosymbiotic theory’ for the origin of eukaryotic cells, which make up complex organisms like humans. This groundbreaking theory proposes that eukaryotic cells arose from symbiotic mergers between once free-living bacterial cells. Because her theory challenged well-established concepts, it was met with widespread criticism and hostility. Notably, her original paper outlining the theory, On the Origin of Mitosing Cells, was famously rejected 15 times before it was finally published in the Journal of Theoretical Biology in 1967. Margulis' ideas were later confirmed in the 1970s when new DNA sequencing technologies provided irrefutable evidence that eukaryotic cells contain bacterial DNA. Today, her serial endosymbiotic theory is a widely accepted cornerstone of evolutionary and cellular biology.

Margulis had four children from two marriages: two sons from her first marriage to the astronomer and author, Carl Sagan, and a son and a daughter from her second marriage to the crystallographer, Thomas Margulis. From the time of her first marriage, she is said to have struggled with balancing her scientific identity with her roles as a woman, spouse, and mother. A visitor to the family home once recalled:


“… He expected Lynn to handle all the duties of a 1950’s housewife, from washing dishes to paying the household bills. Unlike most housewives, Lynn was trying to juggle two infants and a demanding husband [Astronomer, Carl Sagan] with getting a doctorate.”   

From the biography “Carl Sagan: A life in the Cosmos” by William Poudstone

She finally got divorced from her second husband in 1980 and remained a solo mother to her four children for the majority of her life. She said “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 embodied many of the qualities that scientists strive for. She was undoubtedly innovative and multidisciplinary, drawing on ideas from geology, paleontology, ecology, cell biology, microbiology, genetics, and biochemistry. Not only was she unafraid to challenge prevailing scientific thinking, but she also had the courage to stand by her ideas, despite facing repeated resistance. This led to her being unfairly described at times as unruly, rebellious, and unorthodox—sadly, the type of criticism that women who dare to challenge the status quo continue to face today. A more accurate description of Margulis was that of a passionate, innovative, and trailblazing scientist, who’s tenacity, grit and resiliency continues to inspire us.

She collaborated with her daughter, Dorian Sagan, on several books and received numerous awards throughout her career. In 1983, she was elected to the National Academy of Sciences, and in 1999, she was awarded the U.S. National Medal of Science. These achievements are all the more remarkable considering the significant challenges women in science faced during that time. Margulis sadly passed away in 2011 after suffering a stroke, at 73 years old. 


Written by Rachel James and Lindsey Fitzsimons
Published on 03 of February, 2025

 
 
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