Lynn Margulis is a theoretical biologist and professor of botany at the University of Massachusetts at Amherst. Her research on the evolutionary links between cells containing nuclei (eukaryotes) and cells without nuclei (prokaryotes) led her to formulate a symbiotic theory of evolution that was initially spurned in the scientific community but has become more widely accepted.

Margulis, the eldest of four daughters, was born in Chicago. Her father, Morris Alexander, was a lawyer who owned a company that developed and marketed a long-lasting thermoplastic material used to mark streets and highways. He also served as an assistant state's attorney for the state of Illinois. Her mother, Leone, operated a travel agency. When Margulis was fifteen, she completed her second year at Hyde Park High School and was accepted into an early entrant program at the University of Chicago.

Margulis was particularly inspired by her science courses, in large...