Evaluation of the endosymbiosis theory
People are remarkably good at ignoring or even altering information that does not fit with preconceived structures, and we are more likely to remember those facts that fit these structures than we are to remember other facts that are inconsistent with them.
Their theories were originally rejected due the assumption that mitochondria and chloroplasts did not contain DNA. Mereshcowsky published his finding of mitochondria in his work, Symbiogenesis and the Origin of Species in collaboration with Ivan Wallin.
Short note on endosymbiotic theory
Margulis proposed that eukaryotic flagella and cilia originated from endosymbiotic spirochetes. In , Dr. However, most scientists working in any particular field including myself have little awareness of these ideas, and they are seldom foremost in our minds when we interpret our data, almost as though we are ourselves experimental subjects but never get the diagnosis needed to be more self-aware of the reflexive nature of scientific theories. Abstract Evolutionary hypotheses are correctly interpreted as products of the data they set out to explain, but they are less often recognized as being heavily influenced by other factors. In mitochondria, protons are pumped to the intermembrane space and drive ATP synthesis. Not only are they different at the cellular level in possessing a nucleus and endomembrane system, cytoskeleton, and semi-autonomous membrane-bounded organelles mitochondria and sometimes plastids , for example, but they also possess different means of replicating and expressing genetic information. Chloroplasts transform light energy into the chemical energy of ATP. Margulis showed convincing research evidence that mitochondria evolved from aerobic bacteria called Proteobacteria, and chloroplasts evolved from endosymbiotic cyanobacteria. This theory died with the recognition that dinoflagellates are not an ancient lineage. These theories for endosymbiotic origins of singular structures like flagella, peroxisomes, and the nucleus grew out of a desire to explain a specific, complex feature of eukaryotic cells. The prisoner prokaryotes might have provided crucial nutrients in the case of the primitive chloroplast or helped to exploit oxygen for extracting energy in the case of the primitive mitochondrion. The process of proposing a scientific hypothesis and testing it with data is well known to everyone practicing research, even if they are not the only ways to do so, but the mechanism by which we accomplish this is itself an imperfect product of evolution and doubtless arose for some entirely different cognitive purpose. Mereschocowky proposed that smaller and less complex cells formed symbiotic relationships with larger complex cells. The Mesokaryote hypothesis has had little impact since it was overturned, but the impact of the Archezoa hypothesis has been more significant, surviving well beyond the hypothesis itself.
This theory proposes that the organelles of eukaryotic cells, specifically the mitochondria and chloroplasts, were once free-floating bacteria that were ingested by larger, prokaryotic bacteria by means of endocytosis.
Chloroplasts transform light energy into the chemical energy of ATP.
Similar stories were told and eventually disproven or largely forgotten for the endoplasmic reticulum, glycosomes, peroxisomes, cytoskeleton, and even the nucleus itself Cavalier-Smith b; Gupta and Golding ; Gupta and Singh ; Lake and Rivera ; Golding and Gupta ; Gupta ; Li and Wu In his trenchant review of these theories, and the nucleus in particular, Martin points out that these hypotheses share a fundamental characteristic that distinguishes them from the hypotheses for an endosymbiotic origin of mitochondria and plastids, whereas the latter were proposed to explain specific similarities between the organelles and particular free-living cells, the former were put forward to explain traits that were complex, but either lacked such a connection to specific free-living cells or were based on superficial similarities that did not stand up to more detailed comparison.
The prokaryotes, in turn, would have received protection and a steady environment in which to live.
based on 55 review