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Holophyletic is a term posited as a semantically correct replacement for the term monophyletic as used by cladists (which differs from the usage of evolutionary systematists).[1] It originated amidst confusion over the correct definition for monophyletic group; many definitions were available, of varying degrees of restrictiveness, and holophyletic was posited as a term to describe the definition with scientific utility.[1] The least scientifically useful definition for monophyletic, which is arguably the semantically correct one, considers any group of organisms that includes its own common ancestor to be a monophyletic group.[2] A naive view would be to say that one can find a common ancestor from any group of organisms, if one goes far enough into the past.[1] But with a little thought it is obvious that this objection stems from a misunderstanding: the question is not whether a common ancestor exists (it does), but whether the common ancestor is itself contained within the group. A monophyletic group contains its common ancestor; a polyphyletic group does not contain its common ancestor.[3]

The term holophyletic refers specifically to the definition that a group contains the common ancestor, all organisms descended from the common ancestor, and no other organisms.

The term holophyletic has not gained widespread acceptance in the scientific community,[4] probably because the term monophyletic is so widely used with the same widely understood meaning.


  1. ^ a b c Ashlock, P.D. (1971). "Monophyly and associated terms". Systematic Zoology 20 (1): 63–69. doi:10.2307/2412223. JSTOR 2412223. 
  2. ^ Envall, Mats (2008). "On the difference between mono-, holo-, and paraphyletic groups: a consistent distinction of process and pattern". Biological Journal of the Linnean Society 94: 217. doi:10.1111/j.1095-8312.2008.00984.x. 
  3. ^ Valentine, James W (2006). On the Origin of Phyla. University of Chicago Press. ISBN 9780-226845494. 
  4. ^ Google Scholar. "Holophyletic".