| In 1977, Woese et al discovered that the bacteria they were working on were very unusual relative to bacteria like E coli. The methanogens, etc. received the name Archaebacteria, meaning ancient bacteria. Woese then reconsidered the name and the organization of life itself. He noted that the Archaebacteria was as different from the Eubacteria as each one was different from the Eykaryota. Thus, he defined three Domains of life that he called Bacteria, Archaea, and Eucarya. Margulis and Schwartz (1998) challenge the idea and suggest that the better way to think of the organization is two superkingdoms: Prokaryota and Eukaryota. I agree that life is organized into two forms: the prokaryote form which is monogenomic (barring the occasional plasmid) and the eukaryotic form that exists as communities of genomes functioning together as a unit. The monogenomic form, although a type, does not form a clade. The two lines of existing bacterial groups are distinctly different. So, I accept that life exists in three types or domains. Two of those are bacterial: the Archaea and Eubacteria. Thus, I treat the domains as Superkingdoms. The organization of those domains varies enormously depending on the source [e.g. Margulis and Schwartz (1998), Garrity et al (2001 and 2003), and Daubin et al (2002)]. |
