A Successive Approximations Approach to Character Weighting

Farris, J. S. (Dept. Biol. Sci., State Univ., Stony Brook, New York 11790) 1969. A successive approximations approach to character weighting. Syst. Zool., 18:374–385.—Characters that are reliable for cladistic inference are those that are consistent with the true phyletic relationships, that is, those that have little homoplasy. A set of cladistically reliable characters are correlated with each other in a particular non-linear fashion here referred to as hierarchic correlation. Cladistically unreliable characters can be hierarchically correlated only by chance. A technique that infers cladistic relationships by successively weighting characters according to apparent cladistic reliability is suggested, and computer simulation tests of the technique are described. Results indicate that the successive weighting procedure can be highly successful, even when cladistically reliable characters are heavily outnumbered by unreliable ones.