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PROBLEMS WITH “SOFT” POLYTOMIES
Author(s) -
Coddington Jonathan A.,
Scharff Nikolaj
Publication year - 1996
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.1096-0031.1996.tb00198.x
Subject(s) - cladistics , interpretation (philosophy) , cladogenesis , ambiguity , phylogenetic tree , mathematics , axiom , testability , biology , computer science , artificial intelligence , statistics , geometry , clade , biochemistry , gene , programming language
— The “soft” assumption attributes polytomies to lack of data, not simultaneous cladogenesis (the “hard” assumption). Most systematists prefer the first interpretation, but most parsimony programs implicitly use the second. Results can thus be inconsistent with initial assumptions. Under certain circumstances that seem especially typical for large data sets treating higher taxa, it may be valid to eliminate both compatible and incompatible polytomous trees from consideration. Consistent treatment of soft polytomies can reduce the ambiguity of cladistic solutions and improve the resolution, and testability, of phylogenetic hypotheses.