For much of her career, the biologist and theorist Lynn Margulis was one of the more revolutionary and controversial figures in modern science. Though she believed in evolution, she waged war against the neo-Darwinist notions that ruthless competition on a genetic level is the main driver of evolution and change. Instead, Margulis posited the notion that symbiosis, cooperation, and bonding between organisms was what created new organisms—a notion that was rejected by many in the scientific community but has recently become more accepted. Indeed, at times, Margulis seemed to be suggesting not just a different scientific approach, but a different cultural approach to understanding the world. For what happens when we think of cooperation and conjoining, and not competition and dominance, as the basis of life and creation? No wonder her ideas were so often rejected by an extremely male scientific establishment.

John Feldman’s reverent, exhaustive documentary seeks to do justice to Margulis’s life and work—it has the feel of a personal movie, even though it offers a wealth of information about the scientist, who died in 2011. However, the filmmaking is largely functional, and the picture is quite long. Margulis’s life and career were quite dramatic, and it might have been interesting and rewarding to lean into those conflicts more, and also to focus this tale more. But Symbiotic Earth is also clearly a labor of love, and those with any interest in Margulis’s work and the history of biology will find much of value here. —BE