Biologist Lynn Margulis is a professor at the
University of Massachusetts Amherst. Probably her most important scientific contribution is the explanation of the origin of
mitochondria as separate organisms that long ago entered a
symbiotic relationship with
eukaryotic cells through
endosymbiosis.
She is a proponent of the Gaia theory, based on an idea developed by the English atmospheric scientist James Lovelock.
She was the first wife of Carl Sagan, and mother of Dorion Sagan[?].