Evolutionary Biology

, Volume 37, Issue 2–3, pp 123–127 | Cite as

Aphyly: A Systematic Designation for a Taxonomic Problem

  • Malte C. EbachEmail author
  • David M. Williams


A taxon is aphyletic when it is deemed to be non-monophyletic or unresolved, therefore aphyletic taxa are a taxonomic problem rather than an evolutionary anomaly. A problem arises in systematics when taxonomic names assigned to aphyletic taxa are treated as if they were natural groups. In the absence of a taxonomic and systematic revision, anomalous taxa should be labelled as aphyletic without recourse to phylogenetic inference (i.e., interpretation). Doing so avoids the validation of aphyletic names and the creation of dubious results in fields that rely on systematic and taxonomic data.


Aphyly Non-monophyly Paraphyly Polyphyly Systematics Taxonomy 



We thank Anthony Gill, Benedikt Hallgrimsson, Gary Nelson, Lynne Parenti and one anonymous reviewer for their helpful comments and suggestions. MCE is grateful to the ARC for awarding a Future Fellowship (FT0992002) and thanks Melinda Tursky and Mr. Purley for their invaluable support.


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.Evolution and Ecology Research CentreSchool of Biological, Earth and Environmental Sciences, University of New South WalesSydneyAustralia
  2. 2.Department of BotanyThe Natural History MuseumLondonUnited Kingdom

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