title: Phylogeny: a non-hyperthermophilic ancestor for bacteria.
abstract: The first phyla that emerge in the tree of life based on ribosomal RNA (rRNA) sequences are hyperthermophilic, which led to the hypothesis that the universal ancestor, and possibly the original living organism, was hyperthermophilic. Here we reanalyse the bacterial phylogeny based on rRNA using a more reliable approach, and find that hyperthermophilic bacteria (such as Aquificales and Thermotogales) do not emerge first, suggesting that the Bacteria had a non-hyperthermophilic ancestor. It seems that Planctomycetales, a phylum with numerous peculiarities, could be the first emerging bacterial group.
authors.affiliation: Phylogénie, Bioinformatique et Génome, UMR 7622 CNRS, Université Pierre et Marie Curie, 9 quai St Bernard, 75005 Paris, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Brochier
authors.forename: Hervé
authors.initials: H
authors.lastname: Philippe
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics; D001419:Bacteria / Q000145:classification* / Q000235:genetics; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D015203:Reproducibility of Results; D021521:Ribotyping; D013696:Temperature
chemical_list: D012329:RNA, Bacterial; D012335:RNA, Ribosomal