You are not currently logged in.
Access JSTOR through your library or other institution:
Paraphyletic and Polyphyletic Groups
Norman I. Platnick
Vol. 26, No. 2 (Jun., 1977), pp. 195-200
Stable URL: http://www.jstor.org/stable/2412841
Page Count: 6
You can always find the topics here!Topics: Biological taxonomies, Polyphyly, Paraphyly, Monophyly, Genera, Taxa, Systematics, Descendants, Phylogenetics, Tariff drawbacks
Were these topics helpful?See something inaccurate? Let us know!
Select the topics that are inaccurate.
Preview not available
Previously proposed definitions of the terms monophyletic, paraphyletic, and polyphyletic are examined. The definitions provided by Hennig and Ashlock are internally flawed because they do not prevent a single group from being simultaneously paraphyletic and polyphyletic. The definitions provided by Nelson are internally consistent but have undesirable consequences by either precluding the existence of monotypic genera or allowing coordinate taxa to both correspond and not correspond to monophyletic groups. The definitions provided by Farris are internally consistent and lack the drawbacks of Nelson's views; it is suggested that they are successful because they identify necessary relationships between the concepts of polyphyly and parallelism and the concepts of paraphyly and character reversal.
Systematic Zoology © 1977 Oxford University Press