MitochondriaEndosymbiont HypothesisEpisome HypothesisDuplicationCompartimentalisationEnslavement HypothesisThe endosymbiont and episome theories about the origin of mitochondria are reviewed. Biochemical and genetic data, relevant to these theories are discussed. An alternative theory is also proposed; this theory...
and that the initial benefit of the symbiosis might have been the endosymbiont's ability to detoxify oxygen for the anaerobe host. Because this theory presumes the host to have been a eukaryote already, it does not directly account for the ubiquity of mitochondria. That is, it entails a coro...
It is unparsimonious to assume that such characters were present in and then lost by the ancestors of eukaryotes. Though the replacement of archaebacterial lipids by acyl ester lipids derived from the enslaved proteobacterial ancestor of mitochondria is a formal possibility [26], it would be evo...
The origin of mitochondria is a unique and hard evolutionary problem, embedded within the origin of eukaryotes. The puzzle is challenging due to the egalitarian nature of the transition where lower-level units took over energy metabolism. Contending theories widely disagree on ancestral partners, initi...
A theory of the origin of eukaryotic cells ("higher" cells which divide by classical mitosis) is presented. By hypothesis, three fundamental organelles the mitochondria, the photosynthetic plastids and the (9+2) basal bodies of flagella were themselves once free-living (prokaryotic) cells. The ev...
T he origin of mitochondria was a seminal event in the history of life. It is now widely accepted that mito- chondria evolved only once from bacteria living within their host cells, probably two billion years ago (known as the endosymbiosis theory). Specifically, phylogenetic analyses have ...
3.4 The Mitochondrial Theory of Ageing . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 3.5 Why Are There Genes in Mitochondria? . . . . . . . . . . . . . . . . . . . . . . . . 47 3.6 Co-location of Gene and Gene Product Permits Redox...
The hypothesis of bacterial origin of mitochondria, which existed until the end of the 20th century, has been confirmed on the basis of the current concepts of organic world evolution in the open sea hydrosphere and original data on the entry of bacteria (prokaryotes) in the cells of eukaryotes...
The endosymbiotic theory for the origin of mitochondria requires substantial modification. The three identifiable ancestral sources to the proteome of mitochondria are proteins descended from the ancestral alpha-proteobacteria symbiont, proteins with no homology to bacterial orthologs, and diverse proteins with...
Figure 1. The origin and evolution of mitochondria and eukaryotes. Mitochondria evolved from an endosymbiotic alphaproteobacterium (purple) within an archaeal-derived host cell that was most closely related to Asgard archaea (green). The earliest ancestor of mitochondria (that is not also an ancestor...