If you are going to talk about Archaea, you may want to do a bit more research. For example, http://en.wikipedia.org/wiki/Archaea as a simple start. Archaea are micro-organisms but they are not bacteria. Science is constantly evolving. What you see depends on how you look at it – just like looking at a galaxy in different wavelengths of energy. Traditional microbiological approaches don’t work with Archaea – but mass extractions of nucleic acids from a sample of earth (or your gut) suggest how important they really are. In these analyses, scientists look for unusual nucleic acid sequences.