Symbiogenesis

Symbiogenesis 

a theory stating that many eukaryotic cell structures, including mitochondria, chloroplasts, and kinetic, or mitotic, centers (containing centrioles, blepharoplasts, and flagella), originate as a result of the prolonged symbiosis between eukaryotes and prokaryotes, for example, bacteria and blue-green algae. According to this theory, a mitochondrion is an endosymbiont that originates from a free-living aerobic bacterium that has penetrated an older anaerobic bacterium; as a result, the latter bacterium becomes aerobic.

The mitochondria present in the cells of all eukaryotes, especially those that are bacilliform, resemble certain bacteria in that they continually bend and twist. They are more similar to a whole prokaryotic organism than the other components of a eukaryotic cell, with the exception of chloroplasts. The latter, according to the theory of symbiogenesis, originate from blue-green algae, which, having become the endosymbionts of eukaryotic cells, lose their independence and adapt themselves to performing photosynthesis.

The founders of the theory of symbiogenesis included the Russian and Soviet scientists K. S. Merezhkovskii (1905, 1909), A. S. Famintsyn (1907), and B. M. Kozo-Polianskii (1924, 1937). The theory has recently been developed in research conducted by A. L. Takhtadzhian (1972), the American biologist L. Margules (Sagan) (1967, 1970), and the British biologist J. Bernal (1969).

REFERENCES

Kozo-Polianskii, B. M. Novyi printsip biologii: Ocherk teorii simbiogeneza. Leningrad-Moscow, 1924.
Takhtadzhian, A. L. “Chetyre tsarstva organicheskogo mira.” Priroda, 1973, no. 2, pp. 22–32.