An ancient divergence among the bacteria

Summary The 16S ribosomal RNAs from two species of methanogenic bacteria, the mesophileMethanobacterium ruminantium and the thermophileMethanobacterium thermoautotropbicum, have been characterized in terms of the oligonucleotides produced by digestion withT₁ ribonuclease. These two organisms are found to be sufficiently related that they can be considered members of the same genus or family. However, they bear only slight resemblance to typical Procaryotic genera; such asEschericbia, Bacillus andAnacystis. The divergence of the methanogeinc bacteria from other bacteria may be the most ancient phylogenetic event yet detected — antedating considerably the divergence of the blue green algal line for example, from the main bacterial line.