Editing Three-domain system (section)

==Niches==
Each of the three cell types tends to fit into recurring specialities or roles. Bacteria tend to be the most prolific reproducers, at least in moderate environments. Archaeans tend to adapt quickly to extreme environments, such as high temperatures, high acids, high sulfur, etc. This includes adapting to use a wide variety of food sources. Eukaryotes are the most flexible with regard to forming cooperative colonies, such as in multi-cellular organisms, including humans. In fact, the structure of a eukaryote is likely to have derived from a joining of different cell types, forming [[organelle]]s.

''[[Parakaryon myojinensis]]'' (''[[incertae sedis]]'') is a single-celled organism known to be a unique example. "This organism appears to be a life form distinct from [[prokaryotes]] and [[eukaryotes]]",<ref name=yamaguchi>{{cite journal | vauthors = Yamaguchi M, Mori Y, Kozuka Y, Okada H, Uematsu K, Tame A, Furukawa H, Maruyama T, Worman CO, Yokoyama K | title = Prokaryote or eukaryote? A unique microorganism from the deep sea | journal = Journal of Electron Microscopy | volume = 61 | issue = 6 | pages = 423–31 | date = 2012 | pmid = 23024290 | doi = 10.1093/jmicro/dfs062 }}</ref> with features of both.