Lynn Margulis was an American evolutionary theorist, taxonomist, bacteriologist, protistologist, and botanist, with advanced degrees in zoology and genetics.Born on March 5, 1938 in Chicago, Illinois. Margulis was raised in Chicago. Intellectually precocious, she graduated with a bachelor’s degree from the University of Chicago in 1957. Soon after, she married American astronomer Carl Sagan, with whom she had two children; one, Dorion, would become her frequent collaborator. The couple divorced in 1964. Margulis earned a master’s degree in zoology and genetics from the University of Wisconsin at Madison in 1960 and a Ph.D. in genetics from the University of California, Berkeley, in 1965. She joined the biology department of Boston University in 1966 and taught there until 1988, when she was named distinguished university professor in the department of botany at the University of Massachusetts at Amherst. She retained that title when her affiliation at the university changed to the department of biology in 1993 and then to the department of geosciences in 1997. Lynn Margulis died of a hemorrhagic stroke on November 22, 2011. She was 73 years old.