The Elements of Evolution (33-4) Symbiogenesis

Symbiogenesis

The view of Linnaeus and most biologists – Nature does not make leaps – is not correct, since formation from two (or more) organisms of a third is a leap. ~ Boris Kozo-Polyansky in 1921

Symbiogenesis – that eukaryotes arose via symbiosis – was first suggested by German botanist Andreas Schimper in 1883. In 1905, Russian biologist and botanist Konstantin Mereschkowski outlined a theory that the organelles of complex cells evolved from symbiotic relationships with simpler ones. He came to this concept after studying lichen, which are a composite life form. French biologist Paul Portier claimed in 1918 that mitochondria resulted from symbiosis. In 1924, Russian botanist Boris Kozo-Polyansky cast symbiogenesis in a conventional Darwinian context, albeit trying to flip “survival of the fittest” on its head.

The theory of symbiogenesis is a theory of selection relying on the phenomenon of symbiosis. ~ Boris Kozo-Polyansky

The theory didn’t take. Though others made similar proposals, symbiogenesis was ridiculed and ignored for over a half century.

The eukaryotic cell is the result of the evolution of ancient symbioses. ~ Lynn Margulis

Lynn Margulis revisited symbiogenesis in 1967, proposing that eukaryotes evolved via the symbiosis of prokaryotes. Her theory was ignored for a decade, until substantiated via genetic analysis. The symbiogenesis of eukaryotes is now universally accepted.

Margulis went on to generalize the importance of mutualism in evolution.

The view of evolution as a chronic bloody competition among individuals and species, a popular distortion of Darwin’s notion of “survival of the fittest,” dissolves before a new view of continual cooperation, strong interaction, and mutual dependence among life forms. Life did not take over the globe by combat, but by networking. ~ Lynn Margulis