Kingdom (biology)

taxonomic rank

Kingdom is the highest rank, after the domain, which is normally used in the biological taxonomy of all organisms. Each kingdom is split into phyla.

There are 5 to 7 kingdoms in taxonomy. Every living thing comes under one of these kingdoms and some symbionts, such as lichen, come under two. There are at least:

Overview

change
Linnaeus
1735[1]
Haeckel
1866[2]
Chatton
1925[3][4]
Copeland
1938[5][6]
Whittaker
1969[7]
Woese et al.
1977[8][9]
Woese et al.
1990[10]
Cavalier-Smith
1993[11][12][13]
Cavalier-Smith
1998[14][15][16]
2 kingdoms 3 kingdoms 2 empires 4 kingdoms 5 kingdoms 6 kingdoms 3 domains 8 kingdoms 6 kingdoms
(not treated) Protista Prokaryota Monera Monera Eubacteria Bacteria Eubacteria Bacteria
Archaebacteria Archaea Archaebacteria
Eukaryota Protoctista Protista Protista Eucarya Archezoa Protozoa
Protozoa
Chromista Chromista
Vegetabilia Plantae Plantae Plantae Plantae Plantae Plantae
Fungi Fungi Fungi Fungi
Animalia Animalia Animalia Animalia Animalia Animalia Animalia

The kingdom-level classification of life is still widely employed as a useful way of grouping organisms. Sometimes entries in the table, which are next to each other, do not match perfectly. For example, Haeckel placed the red algae (Haeckel's Florideae; modern Rhodophyta) and blue-green algae (Haeckel's Archephyta; modern Cyanobacteria) in his Plantae, but in modern classifications they are considered protists and bacteria respectively. However, despite these differences, the table gives a useful summary.

  • There is no agreement at present on how many kingdoms there are in the Eukarya. In 2009, Andrew Roger and Alastair Simpson said this: "With the current pace of change in our understanding of the eukaryote tree of life, we should proceed with caution".[17]
change

References

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  1. Linnaeus, C. (1735). Systemae Naturae, sive regna tria naturae, systematics proposita per classes, ordines, genera & species.
  2. Haeckel, E. (1866). Generelle Morphologie der Organismen. Reimer, Berlin.
  3. Chatton, É. (1925). "Pansporella perplexa. Réflexions sur la biologie et la phylogénie des protozoaires". Annales des Sciences Naturelles - Zoologie et Biologie Animale. 10-VII: 1–84.
  4. Chatton, É. (1937). Titres et Travaux Scientifiques (1906–1937). Sette, Sottano, Italy.
  5. Copeland, H. (1938). "The kingdoms of organisms". Quarterly Review of Biology. 13: 383–420. doi:10.1086/394568.
  6. Copeland, H. F. (1956). The Classification of Lower Organisms. Palo Alto: Pacific Books. doi:10.5962/bhl.title.4474.
  7. Whittaker, R. H. (January 1969). "New concepts of kingdoms of organisms". Science. 163 (3863): 150–60. Bibcode:1969Sci...163..150W. doi:10.1126/science.163.3863.150. PMID 5762760.
  8. Woese, C. R.; Balch, W. E.; Magrum, L. J.; Fox, G. E.; Wolfe, R. S. (August 1977). "An ancient divergence among the bacteria". Journal of Molecular Evolution. 9 (4): 305–311. doi:10.1007/BF01796092. PMID 408502.
  9. Woese, C. R.; Fox, G. E. (November 1977). "Phylogenetic structure of the prokaryotic domain: the primary kingdoms". Proceedings of the National Academy of Sciences of the United States of America. 74 (11): 5088–90. Bibcode:1977PNAS...74.5088W. doi:10.1073/pnas.74.11.5088. PMC 432104. PMID 270744.
  10. Woese, C.; Kandler, O.; Wheelis, M. (1990). "Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya". Proceedings of the National Academy of Sciences of the United States of America. 87 (12): 4576–9. Bibcode:1990PNAS...87.4576W. doi:10.1073/pnas.87.12.4576. PMC 54159. PMID 2112744.
  11. Cavalier-Smith T. 1981. Eukaryote kingdoms: seven or nine?. Bio Systems 14 (3–4): 461–481. [1]
  12. Cavalier-Smith T. 1992. Origins of secondary metabolism. Ciba Foundation Symposium 171: 64–80; discussion 80–7. [2]
  13. Cavalier-Smith T. 1993. Kingdom protozoa and its 18 phyla. Microbiological Reviews 57 (4): 953–994. [3]
  14. Cavalier-Smith, T. (1998), "A revised six-kingdom system of life", Biological Reviews, 73 (03): 203–66, doi:10.1111/j.1469-185X.1998.tb00030.x, PMID 9809012
  15. Cavalier-Smith, T. (2004), "Only six kingdoms of life" (PDF), Proceedings of the Royal Society of London B Biological Sciences, 271: 1251–62, doi:10.1098/rspb.2004.2705, PMC 1691724, PMID 15306349, retrieved 2010-04-29
  16. Cavalier-Smith T (June 2010). "Kingdoms Protozoa and Chromista and the eozoan root of the eukaryotic tree". Biol. Lett. 6 (3): 342–5. doi:10.1098/rsbl.2009.0948. PMC 2880060. PMID 20031978.
  17. Roger, A.J. & Simpson, A.G.B. (2009), "Evolution: Revisiting the root of the eukaryote tree", Current Biology, 19 (4): R165–7, doi:10.1016/j.cub.2008.12.032, PMID 19243692, S2CID 13172971