Cells starting by rapid evolution?

             In the 1970s biologist Lynn Margulis proposed that complex cells did not evolve by small mutational steps from bacterial cells, but by symbiotic associations of different kinds of bacteria that became higher level organisms in their own right. Although, in 1990s, evolutionary biologists John M. Smith and Eors Szathary proposed that similar major transitions occurred throughout the history of life, including the evolution of the first cells, the event of multicellular organisms, and the development of social insect colonies. They also suggested it could explain the origin of life, with groups of cooperating molecular reactions coming together to create the first life forms.