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Discussion # 1 Symbiogenesis. By Richard Groover For In Search of Symbiosis EVPP 991 - Spring 2010. Symbiogenesis. What is it ? Why is it important ? How has the concept evolved ?
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Discussion # 1Symbiogenesis By Richard Groover For In Search of Symbiosis EVPP 991 - Spring 2010
Symbiogenesis What is it ? Why is it important ? How has the concept evolved ? Where might we find examples in the PRV ?
Definitions to note …. Symbiosis: An ecological relationship between two organisms of two different species that live together in direct contact (Campbell et al. 1999). Symbiont: The smaller participant in a symbiotic relationship, living in or on the host (Campbell et al. 1999).
Symbiogenesis, what is this: Symbiotic relationships that result in a fusion of the entities, resulting in the formation of a new species (Roossinck 2008). The origin of organisms through the combination or association of two or more beings that enter in symbiosis (Merzhkowsky). Symbiogenesis is an evolutionary mechanism (Margulis 1990).
Symbiogenesis “originator” Konstantin Mereschkowsky (1905)
Endosymbiotic theory includes: Eukaryotes formed from Prokaryotes engulfing other cells, and those cells were not internally digested … and remained as organelles in the “host” cell. So, mitochondria and chloroplast were formed this way.
Why is it important ? Provides sound basis for Cell Theory Provides a basis to discover understandings on Systems Function Provides the foundation for Endosymbiotic Theory
Champion of Symbiogenesis & Endosymbiosis Lynn Margulis (2000)
History of Symbiogenesis Theory 1879 H.A. DeBary coined “Symbiosis” (unlike organisms living together) 1905 K.S. Mereschkovsky coined “symbiogenesis” (origin of evolutionary novelty via symbiosis) 1920’s I.E. Wallin advanced the connection with Darwinism 1980 The fields of Endocytobiology was emgering
Where might we find examples in the PRV ? Jellyfish & fin-fish species (harvestfish & butterfly fish) Alpheid shrimp & Xanthoid crab
Parting Thought Is symbiosis more of a lower organism/higher level event and less of a higher / higher level organism event …
Literature Cited or Used Campbell, N.A., Reece, J.B., Mitchell, L.G. 1999. Biology, 5th edition. Benjamin/Cummings, Menlo Park, CA. Margulis, L. 1990. Words as Battle Cries: symbiogenesis and the new field of endocytobiology. Bioscience, 40: 673 – 677. Roossinck, M.J. 2008. Symbiosis, mutualism and symbiogenesis. Plant Virus Evolution. Springer-Verlag, Berlin Vellai, T. and Vida, G. 1999. The origin of eukaryotes: the differences between prokaryotes and eukaryotes cells. Proceedings: Biological Sciences. 266: 1571 – 1577. Wikipedia (photos)