Phylogeny: a non-hyperthermophilic ancestor for bacteria

Nature. 2002 May 16;417(6886):244. doi: 10.1038/417244a.


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.

MeSH terms

  • Archaea / classification
  • Archaea / genetics
  • Bacteria / classification*
  • Bacteria / genetics
  • Phylogeny*
  • RNA, Bacterial / genetics
  • RNA, Ribosomal / genetics
  • Reproducibility of Results
  • Ribotyping
  • Temperature*


  • RNA, Bacterial
  • RNA, Ribosomal