Lynn Margulis_

Lynn Margulis was an American evolutionary biologist, who was the primary modern proponent for the significance of symbiosis in evolution. In particular, Margulis transformed and fundamentally framed biologists' understanding of the evolution of the Eukaryotes, organisms with nuclei in their cells. She proposed that they came into being by symbiotic mergers of bacteria. Margulis was the co-developer of the Gaia hypothesis with the British chemist James Lovelock, proposing that the Earth functions as a unified self-regulating system, and the principal defender and promulgator of the five kingdom classification of Robert Whittaker.