Circumscription (taxonomy)
Look up circumscription in Wiktionary, the free dictionary.
In
Botanical
Nomenclature, and must be reached by scientific consensus.
A goal of biological taxonomy is to achieve a stable circumscription for every taxon. This goal conflicts, at times, with the goal of achieving a
paraphyletic
(a group containing some but not all of the descendants of the common ancestor).
For example, the family
Gorilla), but not humans (Homo), which are placed in Hominidae. Once molecular phylogenetic data showed that chimpanzees were more closely related to humans than to gorillas or orangutans,[1] it became clear that Pongidae is a paraphyletic group, and the circumscription of Hominidae was changed to include all four extant genera of great apes
.
Sometimes, systematists propose novel circumscriptions that do not address paraphyly. For example, the broadly circumscribed monophyletic moth superfamily Pyraloidea can be split into two families, Pyralidae and Crambidae, which are reciprocally monophyletic sister taxa.[2]
An example of a botanical group with unstable circumscription is
Podoaceae, which are sometimes considered to be separate families.[4]
See also
References
- ^ Perelman, Polina, Warren E. Johnson, Christian Roos, Hector N. Seuánez, Julie E. Horvath, Miguel AM Moreira, Bailey Kessing et al. "A molecular phylogeny of living primates." PLoS Genet 7, no. 3 (2011): e1001342.
- ^ Nuss, M., B. Landry, R. Mally, F. Vegliante, A. Tränkner, F. Bauer, J. Hayden, A. Segerer, R. Schouten, H. Li, T. Trofimova, M. A. Solis, J. De Prins & W. Speidel 2003–2020: Global Information System on Pyraloidea. - www.pyraloidea.org
- ^ Anacardiaceae Archived March 15, 2005, at the Wayback Machine in L. Watson and M.J. Dallwitz (1992 onwards). The families of flowering plants. Archived December 13, 2010, at the Wayback Machine
- ^ Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 [and more or less continuously updated since].