Editing Clade (section)

==Definition==
{{Main|Phylogenetic nomenclature}}
[[File:Cladogram Crocodilia NL.PNG|thumb|right|upright|Gavialidae, Crocodylidae and Alligatoridae are clade names that are here applied to a [[Phylogenetics|phylogenetic]] tree of crocodylians.]]

A clade is by definition [[monophyletic]], meaning that it contains one ancestor which can be an organism, a population, or a species and all its descendants.<ref group=note>
A semantic case has been made in 2008 that the name should be "holophyletic", but this term has not acquired widespread use. For more information, see ''[[holophyly]]''.</ref><ref>{{cite web|title=International Code of Phylogenetic Nomenclature. Version 4c. Chapter I. Taxa.|url=http://www.ohio.edu/phylocode/art1-3.html|year=2010|access-date=22 September 2012|archive-date=15 June 2010|archive-url=https://web.archive.org/web/20100615072940/http://www.ohio.edu/phylocode/art1-3.html|url-status=dead}}</ref><ref>{{cite journal
 | doi = 10.1111/j.1095-8312.2008.00984.x
 | title = On the difference between mono-, holo-, and paraphyletic groups: a consistent distinction of process and pattern
 | year = 2008
 | last = Envall
 | first= Mats
 | journal = Biological Journal of the Linnean Society
 | volume = 94
 | page = 217 | doi-access = free
 }}</ref> The ancestor can be known or unknown; any and all members of a clade can be extant or extinct.