by Lynn Margulis and Dorian Sagan
This piece was originally published in Home! A Bioregional Reader, edited by Van Andruss, Christopher Plant, Judith Plant, and Eleanor Wright, New Society Publishers, copyright 1990.
Competition in which the strong wins has been given a good deal more press than cooperation. But certain specifically weak organisms have survived in the long run by being part of collectives, while the so-called strong ones, never learning the trick of cooperation, have been dumped on to the scrap heap of evolutionary extinction.
Excerpted from Microcosmos: Four Billion Years of Microbial Evolution, New York: Summit Books, 1986.

Lynn Margulis (1938-2011) was a biologist and writer whose work dramatically transformed the modern understanding of of the importance of symbiosis in evolution and the evolution of cells with nuclei. She received the National Medal of Science from President Bill Clinton in 1999.

Dorian Sagan (b. 1959) is a writer and the son of Lynn Margulis and Carl Sagan. His many publishing credits include a number of books co-written with his mother, as well as a biography of her.