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The Common Ancestor of Archaea and Eukarya Was Not an Archaeon

It is often assumed that eukarya originated from archaea. This view has been recently supported by phylogenetic analyses in which eukarya are nested within archaea. Here, I argue that these analyses are not reliable, and I critically discuss archaeal ancestor scenarios, as well as fusion scenarios f...

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Autor principal: Forterre, Patrick
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Hindawi Publishing Corporation 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3855935/
https://www.ncbi.nlm.nih.gov/pubmed/24348094
http://dx.doi.org/10.1155/2013/372396
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author Forterre, Patrick
author_facet Forterre, Patrick
author_sort Forterre, Patrick
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description It is often assumed that eukarya originated from archaea. This view has been recently supported by phylogenetic analyses in which eukarya are nested within archaea. Here, I argue that these analyses are not reliable, and I critically discuss archaeal ancestor scenarios, as well as fusion scenarios for the origin of eukaryotes. Based on recognized evolutionary trends toward reduction in archaea and toward complexity in eukarya, I suggest that their last common ancestor was more complex than modern archaea but simpler than modern eukaryotes (the bug in-between scenario). I propose that the ancestors of archaea (and bacteria) escaped protoeukaryotic predators by invading high temperature biotopes, triggering their reductive evolution toward the “prokaryotic” phenotype (the thermoreduction hypothesis). Intriguingly, whereas archaea and eukarya share many basic features at the molecular level, the archaeal mobilome resembles more the bacterial than the eukaryotic one. I suggest that selection of different parts of the ancestral virosphere at the onset of the three domains played a critical role in shaping their respective biology. Eukarya probably evolved toward complexity with the help of retroviruses and large DNA viruses, whereas similar selection pressure (thermoreduction) could explain why the archaeal and bacterial mobilomes somehow resemble each other.
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spelling pubmed-38559352013-12-16 The Common Ancestor of Archaea and Eukarya Was Not an Archaeon Forterre, Patrick Archaea Review Article It is often assumed that eukarya originated from archaea. This view has been recently supported by phylogenetic analyses in which eukarya are nested within archaea. Here, I argue that these analyses are not reliable, and I critically discuss archaeal ancestor scenarios, as well as fusion scenarios for the origin of eukaryotes. Based on recognized evolutionary trends toward reduction in archaea and toward complexity in eukarya, I suggest that their last common ancestor was more complex than modern archaea but simpler than modern eukaryotes (the bug in-between scenario). I propose that the ancestors of archaea (and bacteria) escaped protoeukaryotic predators by invading high temperature biotopes, triggering their reductive evolution toward the “prokaryotic” phenotype (the thermoreduction hypothesis). Intriguingly, whereas archaea and eukarya share many basic features at the molecular level, the archaeal mobilome resembles more the bacterial than the eukaryotic one. I suggest that selection of different parts of the ancestral virosphere at the onset of the three domains played a critical role in shaping their respective biology. Eukarya probably evolved toward complexity with the help of retroviruses and large DNA viruses, whereas similar selection pressure (thermoreduction) could explain why the archaeal and bacterial mobilomes somehow resemble each other. Hindawi Publishing Corporation 2013-11-17 /pmc/articles/PMC3855935/ /pubmed/24348094 http://dx.doi.org/10.1155/2013/372396 Text en Copyright © 2013 Patrick Forterre. https://creativecommons.org/licenses/by/3.0/ This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Review Article
Forterre, Patrick
The Common Ancestor of Archaea and Eukarya Was Not an Archaeon
title The Common Ancestor of Archaea and Eukarya Was Not an Archaeon
title_full The Common Ancestor of Archaea and Eukarya Was Not an Archaeon
title_fullStr The Common Ancestor of Archaea and Eukarya Was Not an Archaeon
title_full_unstemmed The Common Ancestor of Archaea and Eukarya Was Not an Archaeon
title_short The Common Ancestor of Archaea and Eukarya Was Not an Archaeon
title_sort common ancestor of archaea and eukarya was not an archaeon
topic Review Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3855935/
https://www.ncbi.nlm.nih.gov/pubmed/24348094
http://dx.doi.org/10.1155/2013/372396
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