Domain (biology)
In biological taxonomy, a domain (also superregnum, superkingdom, empire, or regio) is the highest taxonomic rank of organisms, higher than a kingdom. According to the three-domain system of Carl Woese, introduced in 1990, the Tree of Life consists of three domains: Archaea, Bacteria and Eukarya.[1] The arrangement of taxa reflects the fundamental differences in the genomes. Alternative classifications of life so far proposed include:
- The two-empire system or superdomain system, with top-level groupings of Prokaryota (or Monera) and Eukaryota.[2]
- The six-kingdom system with top-level groupings of Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia.[3]
- The three-empire system (Eubacteria, Archaea, Eukarya) with five supergroups in the Eukarya (Unikonta, Excavata, Chromalveolata, Rhizaria and Archaeplastida)[2][4][5]
None of the three systems currently include non-cellular life.
See also
References
- ^ Woese C, Kandler O, Wheelis M (1990). "Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya.". Proc Natl Acad Sci USA 87 (12): 4576–9. Bibcode 1990PNAS...87.4576W. doi:10.1073/pnas.87.12.4576. PMC 54159. PMID 2112744. http://www.pnas.org/cgi/reprint/87/12/4576. Retrieved 11 February 2010.
- ^ a b Mayr, Ernst (1998). "Two empires or three?.". Proc Natl Acad Sci USA 95 (17): 9720–9723. Bibcode 1998PNAS...95.9720. doi:10.1073/pnas.95.17.9720. http://www.pnas.org/content/95/17/9720.full. Retrieved 5 Sept 2011.
- ^ Cavalier-Smith, T. (2004), "Only six kingdoms of life", Proc. R. Soc. Lond. B 271: 1251–62, doi:10.1098/rspb.2004.2705, PMC 1691724, PMID 15306349, http://www.cladocera.de/protozoa/cavalier-smith_2004_prs.pdf, retrieved 2010-04-29
- ^ Campbell, N. A., et al. (2008) "Biology." 8th edition. Person International Edition, San Francisco
- ^ Holt, Jack R. and Carlos A. Iudica, (2010) "Taxa of Life." Retrieved 09-03-2011.