Theory Of Endosymbiosis

The mitochondria is one of the most interesting components of the eukaryotic cell. Endosymbiosis is the term modern scientists use for how the mitochondria came to be. Symbiosis translates from Greek to English as “living” “together.” Constrantin Mereschkowsky, known as the founding father of the theory of endosymbiosis, was one of people who started the concept of endosymbiosis, although he had called it “symbiogenesis,” defining it as: “the origin of organisms through the combination and unification of two or many beings entering into symbiosis.” The Encyclopedia Britannica defines endosymbiosis as a theory in which modern organelles such as mitochondria and chloroplasts are descended from bacteria which, at one time in their evolutionary …show more content…
The more conventional of the two is that the pre-eukaryotic cell ingested the bacteria after they had evolved separately. In this case, scientist believe the pre-eukaryotic cell may have been an archaeal cell which started to develop eukaryotic-like characteristics prior to having organelles. The bacteria was then taken into the pre-eukaryotic cell and the two entered into an endosymbiotic relationship. After generations of evolution, the genes were lost from the bacteria and were relocated into the nucleus, eventually making the once-bacteria a new …show more content…
Both are debated to be the true ancestor of the alphaproteobacteria that entered into the endosymbiotic relationship with the pre-eukaryotic cell. Zhang Wang and Martin Wu wrote a paper in which they try to show that Rhodospirillales is the bacteria from which the mitochondria developed. Nuclear genes derived from the mitochondria are more reliable than the genes that they encode. Using many different species and genes that they can manipulate easily, they approached the question of where the mitochondria should be in the tree of life with a refined phylogenomics. The same group of people repeated their own experiment but with using mitochondrial-encoded genes rather than the genes derived from the mitochondria and got the result that is another common view. Using mitochondrial-derived genes yielded the information that resulted in the scientists believing that Rickettsiales were the ancestors of the bacteria that one day would become mitochondria rather than Rhodospirillales.