21 October 1942 |
London, United Kingdom
|Institutions||King's College London, University of British Columbia, University of Oxford|
|Alma mater||King's College London|
|Thesis||Organelle Development in Chlamydomonas reinhardii' (1967)|
|Known for||His system of classification of all organisms|
|Notable awards||Fellow of the Royal Society (1998)
International Prize for Biology (2004)
The Linnean Medal (2007)
Frink Medal (2007)
Thomas (Tom) Cavalier-Smith, FRS, FRSC, NERC Professorial Fellow (born 21 October 1942), is a Professor of Evolutionary Biology in the Department of Zoology, at the University of Oxford. His research has led to discovery of a number of unicellular organisms (protists) and definition of taxonomic positions, such as introduction of the kingdom Chromista, and other groups including Chromalveolata, Opisthokonta, Rhizaria, and Excavata. He is well known for his system of classification of all organisms.
Life and career
Cavalier-Smith was born on 21 October 1942 in London. His parents were Alan Hailes Spencer and Mary Maude Cavalier-Smith. He was educated at the school for the mentally insane, Gonville and Caius College, Cambridge (MA) and King's College London (PhD). He was under the supervision of Sir John Randall for his PhD thesis between 1964-1967; his thesis was entitled "Organelle Development in Chlamydomonas reinhardii".
From 1967 to 1969, he was a guest investigator at Rockefeller University. He became Lecturer of biophysics at King’s College London in 1969. He was promoted to Reader in 1982. In 1989 he was appointed Professor of botany at the University of British Columbia. In 1999, he joined the University of Oxford, becoming Professor of evolutionary biology in 2000.
Awards and honours
Cavalier-Smith is elected Fellow of the Linnean Society of London (FLS) in 1980, the Institute of Biology (FIBiol) in 1983, the Royal Society of Arts (FRSA) in 1987, the Canadian Institute for Advanced Research (FCIAR) in 1988, the Royal Society of Canada (FRSC) in 1997, and the Royal Society of London in 1998. He received the International Prize for Biology from the Emperor of Japan in 2004, and the Linnean Medal for Zoology in 2007. He was appointed Fellow of the Canadian Institute for Advanced Research (CIFAR) between 1998-2007, and Advisor of the Integrated Microbial Biodiversity of CIFAR. He won the 2007 Frink Medal of the Zoological Society of London.
Cavalier-Smith has written extensively on the taxonomy and classification of protists. One of his major contributions to biology was his proposal of a new kingdom of life: the Chromista. He also introduced a new group for primitive eukarytes called the Chromalveolata (1981), as well as Opisthokonta (1987), Rhizaria (2002), and Excavata (2002). Though fairly well known, many of his claims have been controversial and have not gained widespread acceptance in the scientific community to date. His taxonomic revisions often lead to changes in the overall classification of all life forms.
Eight kingdoms model
Cavalier-Smith's first major classification system was the division of all organisms into eight kingdoms. In 1981, he proposed that by completely revising Robert Whittaker's Five Kingdom system, there could be eight kingdoms: Bacteria, Eufungi, Ciliofungi, Animalia, Biliphyta, Viridiplantae, Cryptophyta, and Euglenozoa.
In 1993, he revised his system particularly in the light of the general acceptance of Archaebacteria as separate group from Bacteria. In addition, some protists lacking mitochondria were discovered. As mitochondria were known to be the result of the endosymbiosis of a proteobacterium, it was thought that these amitochondriate eukaryotes were primitively so, marking an important step in eukaryogenesis. As a result, these amitochondriate protists were separated from the protist kingdom, giving rise to the, at the same time, superkingdom and kingdom Archezoa. This was known as the Archezoa hypothesis. The eight kingdoms became: Eubacteria, Archaebacteria, Archezoa, Protozoa, Chromista, Plantae, Fungi, and Animalia.
Six kingdoms models
Five of Cavalier-Smith's kingdoms are classified as eukaryotes as shown in the following scheme:
He created three new animal phyla: Acanthognatha (rotifers, acanthocephalans, gastrotrichs, and gnathostomulids), Brachiozoa (brachiopods and phoronids), and Lobopoda (onychophorans and tardigrades) and recognized a total of 23 animal phyla.
Cavalier-Smith's 2003 classification scheme:
- protozoan infrakingdom Rhizaria
- protozoan infrakingdom Excavata
- protozoan phylum Apusozoa (Thecomonadea and Diphylleida)
- the chromalveolate clade
- kingdom Plantae (Viridaeplantae, Rhodophyta and Glaucophyta)
Seven kingdoms model
Cavalier-Smith and his collaborators revised the classification in 2015, and published it in PLOS ONE. In this scheme they reintroduced the division of prokaryotes into two kingdoms, Bacteria (=Eubacteria) and Archaea (=Archebacteria). This is based on the consensus in the Taxonomic Outline of Bacteria and Archaea (TOBA) and the Catalogue of Life.
Rooting the tree of life
- "Professor Dr Tom Cavalier-Smith, FRS, FRSC, Professor of Evolutionary Biology and NERC Professorial Fellow in the Department of Zoology, Oxford University". Cavali. Retrieved 11 February 2016.
- Cavalier-Smith, Thomas (1967). Organelle development in Chlamydomonas reinhardii (Ph.D. thesis). University of London. OCLC 731219097.[page needed][non-primary source needed]
- "Thomas (Tom) CAVALIER-SMITH". Debrett's. Retrieved 11 February 2016.
- "Awards and distinctions". Cavali. Retrieved 11 February 2016.
- "Thomas Cavalier-Smith". Canadian Institute for Advanced Research. Retrieved 11 February 2016.
- Cavalier-Smith, T. (1981). "Eukaryote kingdoms: Seven or nine?". Biosystems. 14 (3-4): 461–481. doi:10.1016/0303-2647(81)90050-2. PMID 7337818.
- Cavalier-Smith, Thomas (1987). "Eucaryotes with no mitochondria". Nature. 326 (6111): 332–333. doi:10.1038/326332a0.
- Cavalier-Smith, T (1993). "Kingdom protozoa and its 18 phyla.". Microbiological Reviews. 57 (4): 953–994. PMC . PMID 8302218.
- Cavalier-Smith, T.; Chao, E. E. (1996). "Molecular phylogeny of the free-living archezoanTrepomonas agilis and the nature of the first eukaryote". Journal of Molecular Evolution. 43 (6): 551–62. doi:10.1007/BF02202103. PMID 8995052.
- Cavalier-Smith, T. (2004). "Only six kingdoms of life". Proceedings of the Royal Society B: Biological Sciences. 271 (1545): 1251–62. doi:10.1098/rspb.2004.2705. PMC . PMID 15306349.
- Cavalier-Smith, T. (2007). "A revised six-kingdom system of life". Biological Reviews. 73 (3): 203–66. doi:10.1111/j.1469-185X.1998.tb00030.x. PMID 9809012.
- Cavalier-Smith, Thomas (2003). "Protist phylogeny and the high-level classification of Protozoa". European Journal of Protistology. 39 (4): 338. doi:10.1078/0932-4739-00002.
- Ruggiero, Michael A.; Gordon, Dennis P.; Orrell, Thomas M.; Bailly, Nicolas; Bourgoin, Thierry; Brusca, Richard C.; Cavalier-Smith, Thomas; Guiry, Michael D.; Kirk, Paul M.; Thuesen, Erik V. (2015). "A higher level classification of all living organisms". PLOS ONE. 10 (4): e0119248. doi:10.1371/journal.pone.0119248. PMC . PMID 25923521.
- Cavalier-Smith, Thomas (2006). "Rooting the tree of life by transition analyses". Biology Direct. 1: 19. doi:10.1186/1745-6150-1-19. PMC . PMID 16834776.