Biologist Lynn Margulis, best known for her work on the theory of endosymbiosis, died on 22 November at her home in Amherst, Massachusetts. She was 73.
Endosymbiosis is the process by which two unrelated organisms fuse into one. Early in her career, Margulis proposed that the eukaryotic cell evolved from an endosymbiotic combination of separate bacteria. Specifically, organelles such as mitochondria and chloroplasts, which have their own DNA, would have originally been free bacteria absorbed by another prokaryote. Although it was treated skeptically at first, the idea is now widely accepted as a crucial step in the evolution of eukaryotes.
“She believed in taking a theory and pushing it to the limits and her endosymbiosis work is a perfect example of that,” says Steve Goodwin dean of the College of Natural Sciences at University of Massachusetts Amherst where Margulis was a professor.
“I think she had a sense that there was a tendency among conventional scientists to stop a little too soon,” says Goodwin.
Dr. Margulis is also known for her contribution to the Gaia hypothesis, which suggests that the interactions between earth’s organisms and ecosystems from a single, self-regulating system that promotes optimal conditions for life.
Margulis’ creative approach to research, her depth of knowledge across diverse specialties and her infectious excitement about science set her apart, Goodwin says. “She had a way of making connections between things that other people just wouldn’t normally make,” he adds.
Margulis was born in 1938 in Chicago, Illinois. She enrolled in the University of Chicago at age 14 and graduated in 1957. She earned a master’s in genetics and zoology at the University of Wisconsin in 1960 and a PhD in genetics from the University of California, Berkeley, in 1965.
Margulis co-authored several books along with her son Dorian Sagan, one of two children from her to marriage to astronomer Carl Sagan. Margulis had two other children from a second marriage.
Image credit: University of Massachusetts Amherst