Hello, I have a question based on Taxonomy, or, the arrangement/organization of living things. My question is based on the highest Taxa, the Domain. My question is: The three domains, Archaea, Bacteria, and Eukarya, are set. However, I often hear Archaea interchanged with the word "Archaeabacteria", and Bacteria interchanged with the word "Eubacteria". So according to the individuals using such words, the three Domains can be called Eukarya, Archeabacteria, and Eubacteria. Would this not be contradictory? Calling the two Prokaryotic domains "Archeabacteria" and "Eubacteria" would suggest that both domains are a type of Bacteria, but is that really the case? Are they right to call the domains by those names? Or are Archaea and Bacteria two entirely different entities? I suppose in a sense, I am asking, are Archaea a type of bacteria, or a completely different entity altogether? Because in that case, Archaea should not have their name used interchangeably with the word "Archaeabacteria".
I think it's merely because the lifeforms within both of those domains consist of a single cell and "bacteria" is a shorthand way to refer to single-celled organisms? According to Wikipedia: "...the tree of life consists of three domains: Archaea (a term which Woese created), Bacteria, and Eukarya. The first two are all prokaryotic microorganisms, or single-celled organisms whose cells have no nucleus. All life that has a nucleus and membrane-bound organelles, and most multi-cellular life, is included in the Eukarya..." Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Kingdom Monera), but this classification is outdated. Archaeal cells have unique properties separating them from the other two domains of life: Bacteria and Eukaryota. The Archaea are further divided into four recognized phyla. Classification is difficult because the majority have not been studied in the laboratory and have only been detected by analysis of their nucleic acids in samples from their environment.
