Her groundbreaking theory on the origin of life was rejected 15 times. Then biology proved her right.
Lynn Margulis had the audacity to challenge Darwin. And we're lucky she did.

A photo of Lynn Margulis.
Throughout her prolific and distinguished career, biologist Lynn Margulis made several groundbreaking contributions to science that we take for granted as common knowledge today. For example, she championed James E. Lovelock’s “Gaia concept,” which posited that the Earth self-regulates to maintain conditions for life.
But by far, her most notable theory was symbiogenesis. While it was first written off as “strange” and “aesthetically pleasing” but “not compelling,” it would ultimately prevail, and completely rewrite how we viewed the origin of life itself.
In the late 1960s, Margulis wrote a paper titled "On the Origin of Mitosing Cells," that was quite avant-garde. In it, she proposed a theory: that life evolved through organisms merging together to become inseparable.
In essence, cooperation is the driver of life, not competition and domination. This directly went against Darwin’s “survival of the fittest” principle that was considered gospel in scientific circles. Margulis’ paper was rejected by fifteen journals before getting accepted into the Journal of Theoretical Biology.
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Time would be on Margulis’ side, however. By the late ‘70s and early ‘80s, research proved that the two major building blocks of plants and animals, chloroplasts and mitochondria were at one time independent bacteria. This solidified the fact that on a biological level, connection trumps autonomy for longevity. And now that fact is written in textbooks, with no real story of the adversity it overcame to get there.
While it is customary for most new scientific theories to be met with criticism, especially those that completely shift the current narrative, many have noted that sexism played a key part in Margulis’ initial lack of acceptance. On more than one occasion, she herself had hinted that women were seen as mothers and wives first, and scientists second. She recalled that while married to fellow scientist Carl Sagan that “Carl would finish his sentence, unperturbed” while she was expected to “handle all the duties of a 1950s housewife, from washing dishes to paying the household bills.”
And yet, Margulis would have other ideas that were controversial that had nothing to do with her gender. Most famously, she did not believe that AIDS was caused by HIV, and instead believed it was cause by a syphilis-causing type of bacteria, despite there already being decades of research proving otherwise. That view was seen as an endorsement of AIDS denialism, which undermined prevention and treatment effort. Then later in life, Margulis became a vocal proponent of 9/11 conspiracy theories suggesting government involvement the in Twin Towers attacks.
And yet, perhaps this is one of those “you gotta take the good with the bad” situations. Margulis’ inherent contrarian nature gave us both these unfounded, even harmful stances, in addition to entirely new paradigms that altered our understanding of life itself.
And if nothing else, it illuminated the need for science to include multiple points of view in order to unlock the truth. It seems life is, after all, about coming together.



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A man sleeps peacefully.
Woman snuggled in bed.
Each of those arms has its own brain?
The size of Japan compared to the United States.Image via Wikimedia