Evaluation of the Endosymbiosis Theory

Evaluation of the secern The modern version of the endosymbiosis hypothesis was essential and promoted by Dr. Lynn Margulis in 1970. The term endosymbiosis comes from endo moment within, and symbiosis which occurs when two different species improvement from living and working together (Genetic attainment Learning Center). This opening proposes that the organelles of eukaryotic cells, specifically the mitochondria and chloroplasts, were in one case free-floating bacteria that were ingested by larger, prokaryotic bacteria by means of endocytosis.The legion bacteria benefitted from the engulfment of the organelles as they were able to lean out functions, such as cellular respiration, more efficiently than the host itself could. Therefore, the nonsymbiotic bacteria were not digested, and consequently everyplace time their deoxyribonucleic acid was combined with the host bacterial cells desoxyribonucleic acid to eventually develop a tonic form of cells called eukaryotes.One o f the most eminent pieces of tell that supports the hypothesis is that although prokaryotic cells and eukaryotic cells ar quite distinctive in physiological characteristics, some of the organelles of eukaryotes share a issue forth of staggering similarities with prokaryotes. Like prokaryotes, the mitochondrion and chloroplast both(prenominal) replicate by means of means of double star fission, unlike the eukaryotic cells that contain them, which submit to mitosis.Moreover, prokaryotes and the abovementioned eukaryotic organelles produce circular deoxyribonucleic acid, whereas eukaryotes pick up linear desoxyribonucleic acid. The size of the DNA is as well as a featureor in the theory as the prokaryotic DNA and the DNA of the organelles is similar in size, and much little than that of eukaryotic cells. The dissimilarities between the physical characteristics of the DNA in the eukaryotic nucleus and the DNA in the organelles lead to the impression that the organelles were once bacterial (prokaryotic) symbionts (IUPUI incision of Biology).However, since the DNA in the nucleus and the organelles replicate independently of for each one other, at that place is the possibility that random mutations whitethorn have occurred, thus causing the discrepancies in the DNA over a authoritative period of time. Therefore, this establish is not conclusive deduction that the organelles are possible posterity of ancestral bacteria. Additionally, chloroplasts and mitochondria are surrounded by a double membrane. This provides further evidence to the endosymbiosis theory because it suggests that these organelles were ingested by a immemorial host (Genetic information Learning Center).To inform this circumstance, the host cell ingests the bacterium through phagocytosis a form of endocytosis which results in an additive lipid bilayer formed by the cyst membrane, in addition to the bacteriums inner plasma membrane (IUPUI section of Biology). There is no oth er know cause as to why these organelles have double membranes, other than the widely-accepted endosymbiotic theory. In the demesne of science, a theory is a well-established account based on extensive experiment and observation, and is generally accepted as fact by the scientific community (Genetic attainment Learning Center).Although some of the evidence provided in support of the endosymbiosis hypothesis is not irrefutable, at that place is more evidence is support of the theory, than there is against it. Therefore, in my opinion, the amount of research draw up into this topic over the years and the unhomogeneous evidences that have been unearthed in support of it, as well as the lack of proof against it, lead me to accepting this theory as conclusive. However, I also want to contrast that research is always being done, and in the near future it is possible that scientists may propose new, improved theories.REFERENCES Genetic Science Learning Center (1969, December 31). T he phylogeny of the Cell. Retrieved on October 8, 2012 from http//learn. genetics. utah. edu/content/begin/cells/organelles/ IUPUI Department of Biology (2002, January 14). The Endosymbiotic Theory. Retrieved on October 8, 2012 from http//www. biology. iupui. edu/biocourses/N100/2k2endosymb. html Caprette, D. R. (2008). evolutionary Origin of Mitochondria. Retrieved on October 8, 2012 from http//www. ruf. rice. edu/bioslabs/studies/mitochondria/mitorigin. html