In comparison with Darwinian evolutionists who argue that the formation of new species is a result of mutation followed by natural selection, the Endosymbiotic Theory approaches evolution in differently. In high school, we are taught that evolution is a change through time, provided with classic evidence of the populations of finches in the Galapagos Island.
Under the piles of material study about Darwin’s Theory of Evolution, Endosymbiotic Theory is merely the engulfment of one bacterium by others, forming organelle cells of mitochondria and chloroplast. Many textbooks simply write that an endosymbiont is a common occurrence in the evolution of organisms. It is not common to think that new species evolved from an endosymbiont. However, we may re-construct this conclusion. Students should be given a balance information to understand that Darwin is the first but not the last one who proposed a theory of evolution. Elias and Archibald (2009) published a review on the impact of endosymbiosis on the evolution of the nuclear genome. This paper has a beautiful picture of the Endosymbiotic Theory explaining the origin and diversity of Chromalveolates (once known as algae). It is also mentioned that almost 20% of the nuclear genome of flowering plants Arabidopsis has the cyanobacterial footprints.
Evolution and classification is like two-sided coin they cannot be parted. Classification as a science has been developed, slowly but steadily. It was supported by the discovery of light and electronic microscope. Classification system is re-shaping its form: Starting from Linnaeus, who divided organisms into plants and animals, to Woese, who introduced Domain as the highest taxonomic ranking. As we revise the system so to be closer to the tree of life, taxa disappeared, diversified, blended. Contrary to the most scientists, Margulis kept questioning Woese’s single data -the RNA- in separating (Eu)Bacteria from Archae: “If the RNA of microorganism can change in just few hours (such as Plasmodium), RNA sequence is probably not the best way of defining the greatest of all groups” (Margulis 1998: 67). To this date, the debates among taxonomists and systematists on morphological and molecular characters for species identification and classification are still on going.
References:
Margulis, L. 1998. Symbiotic Planet : A New Look at Evolution, Basic Books, ISBN 0-465-07271-2Elias M, Archibald JM. 2009. Sizing up the genomic footprint of endosymbiosis. BioEssays 31: 1273-1279.
https://www.deviantart.com/…/Endosymbiotic-Theory…
note: this article has been published in author FB
atthecorner 