Eubacteria

The two prokaryotic domains are Eubacteria (bacteria) and Archaea. The Eubacteria are usually called the Bacteria, and the Archaea are sometimes called the Archaebacteria.

In the schematic (left) phylogenetic relationships of the bacteria are shown. Successive phyla of bacteria branched off the Bacterial line – beginning with Aquifex, and ending with the Spirochetes.

Schematic based on Woese's Tree of Life, which is based upon studies of 16s ribosomal RNA. (right)

In approximate order of evolutionary divergence with earliest (oldest) at top. Click on group to visit description:
Aquifex
Thermotoga
Green nonsulfur
Deinococcus
Bacteroides-Flavobacteria
Planctomyces
Gram-positive
Chlamydia
Cyanobacteria
Spirochetes
Green sulfur
Proteobacteria (purple)