endosymbiosis

Term: endosymbiosis

Literally meaning: " living together inside”

Origin: Anc Greek

ενδο-/endo-(= compining form for “inside”, “internal”, “within”)

συμβίωσις/symbiosis(=living toghether)

>συν/syn(=together, with) + βίος/vios(=life)

Coined/History

Three biologists stand out in the history of the theory of endosymbiosis. At first in 1905, Russian scientist Konstantin Merezhkovsky (1855-1921) coined the term “symbiogenesis” to describe “the living together of different kinds of organisms”. In the 1920s American biologist Ivan Wallin (1883-1969) again proposed in his book “Symbionticism and the Origin of Species”, that organelles such as chloroplasts and mitochondria originated as symbiotic bacteria.  This idea was resuscitated by American biologist Lynn Margulis (1938- ) in 1967. She also proposed that organelles such as mitochondria living inside of nucleated cells evolved from ancient independent-living bacteria. “The crucial piece of evidence unavailable to Wallin until just before he died,” writes Margulis, “was the discovery that mitochondria and plastids possess their very own DNA. Wallin knew though that mitochondria and plastids tend to reproduce at different times than do the cells in which they reside—as if demonstrating a residual impulse of their earlier, wilder days.”

Sourses

1. Lynn Margulis, Dorion Sagan: “What Is Life?” University of California Press, 1995, pp. 132-133.
2. Sorin Sonea, Leo Mathieu: “Prokaryotology: A Coherent View.” Les Presses De L'universite De Montreal. 2001; and Sorin Sonea: “A New Bacteriology.” Jones & Bartlett, 1983.

Definition

The theory which supports that certain organelles as mitochondria and chloroplasts  originated as free-living procaryotes that were taken inside another cell giving rise to the first eukaryotic cells.