On the evolutionary descent of organisms and organelles: a global phylogeny based on a highly conserved structural core in small subunit ribosomal RNA

Nucleic Acids Res. 1984 Jul 25;12(14):5837-52. doi: 10.1093/nar/12.14.5837.


To probe the earliest evolutionary events attending the origin of the five known genome types (archaebacterial, eubacterial, nuclear, mitochondrial and plastid), we have analyzed sequences corresponding to a ubiquitous, highly conserved core of secondary structure in small subunit rRNA. Our results support (i) the existence of three primary lineages (archaebacterial, eubacterial, and nuclear), (ii) a specific eubacterial ancestry for plastids and mitochondria (plant, animal, fungal), and (iii) an endosymbiotic, evolutionary origin of the two types of organelle from within distinct groups of eubacteria (blue-green algae (cyanobacteria) in the case of plastids, nonphotosynthetic aerobic bacteria in the case of mitochondria). In addition, our analysis suggests (iv) a biphyletic origin of mitochondria, with animal and fungal mitochondria branching together but separately from plant mitochondria, and (v) a monophyletic origin of plastids. The method described here provides a powerful and generally applicable molecular taxonomic approach towards a global phylogeny encompassing all organisms and organelles.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Biological Evolution*
  • DNA, Mitochondrial / genetics
  • Eukaryotic Cells / physiology
  • Nucleic Acid Conformation
  • Prokaryotic Cells / physiology
  • RNA, Ribosomal / genetics
  • Ribosomes / ultrastructure


  • DNA, Mitochondrial
  • RNA, Ribosomal