An Information-rich Character Weighting Procedure for Parsimony Analysis

Rodrigo, A.G. (1989). An information-rich character weighting procedure for parsimony analysis. New Zealand Natural Sciences 16: 97-103. A weighting procedure is proposed which takes account of prior information pertaining to the characters used in a parsimony analysis. This information comes from specific knowledge about the biology of the group in question, as well as general evolutionary theory. The weighting procedure consists of three stages: (1) an initial parsimony analysis followed by (2) an examination of the character consistency indices and associated character weights, with reassignment of weights based on prior knowledge of the group; and (3) a reanalysis using the weighted data. The procedure is an iterative one, and can be terminated once the resultant tree has converged to a "constant value", or after a predetermined number of runs. The resultant tree may or may not be as short as the most parsimonious tree. It is argued that in taking account of prior information, the proposed procedure is information-rich (IR). Finally, the procedure is shown to be one of a family of IR techniques which are commonly used in parsimony analysis.