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ON MISSING ENTRIES IN CLADISTIC ANALYSIS
Author(s) -
Platnick Norman I.,
Griswold Charles E.,
Coddington Jonathan A.
Publication year - 1991
Publication title -
cladistics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.323
H-Index - 92
eISSN - 1096-0031
pISSN - 0748-3007
DOI - 10.1111/j.1096-0031.1991.tb00042.x
Subject(s) - cladistics , ambiguity , character (mathematics) , missing data , taxon , biology , binary number , evolutionary biology , computer science , artificial intelligence , algorithm , mathematics , statistics , phylogenetics , genetics , paleontology , arithmetic , gene , geometry , programming language
The exact algorithms of two commonly used parsimony programs, Hennig86 by J. S. Farris and PAUP by D. Swofford, sometimes produce different solutions, and sometimes produce resolutions that are not supported by the data being analysed. The discrepancies apparently involve the treatment of missing entries, which can currently represent unknown data, inapplicable character and/or polymorphic taxa. Each of those potential sources of ambiguity is logically (if not computationally) different; with regard to binary characters, unknown data could be either 0 or 1, inapplicable characters are neither 0 nor 1 and polymorphisms are both 0 and 1. Resolutions that cannot be supported by any possible combination of known state attributions should either be flagged as such or suppressed entirely.