Level of life
Organism
An individual living thing, from a single bacterium to a tree or a person.
Archaea
Single-celled organisms without a nucleus that form a separate domain of life from bacteria.Source: Woese & Fox, 1977Source: Woese et al., 1990
Organism or group
How Archaea connects
Archaea is an example of
Archaea is described by
Idea or model
Three domains of life
Comparing ribosomal RNA divides life into three domains: Bacteria, Archaea and Eukarya.
Archaea is related to
Organism or group
Thermophiles
Microbes that thrive in heat, such as Thermus aquaticus from hot springs, the source of a heat-stable enzyme used in PCR.
Studied in
Your progress
Sources & further reading
The explanations on this page are our own summaries of these sources. Follow a link to read the original; if anything here disagrees with it, the original wins. How we choose and check sources.
Phylogenetic structure of the prokaryotic domain: the primary kingdoms (opens the original in a new tab)
Woese CR, Fox GE (1977). Proceedings of the National Academy of Sciences 74:5088-5090.
Ribosomal RNA comparisons revealed the archaea as a separate lineage.
Peer-reviewedPrimary researchTowards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya (opens the original in a new tab)
Woese CR, Kandler O, Wheelis ML (1990). Proceedings of the National Academy of Sciences 87:4576-4579.
Peer-reviewedPerspective