PARSIMONY ANALYSIS AS A SPECIFIC KIND OF HOMOLOGY ESTIMATION AND THE IMPLICATIONS FOR CHARACTER WEIGHTING

''Remane-Hennigian systematists'' still reject parsimony analysis for phylogenetics, because homology or apomorphy analyses are not included . In contrast, ''pattern cladists'' regard homology as a deductive con cept after applying a parsimony test of character congruence. However, as in molecular phylogeny, selection of ''good'' characters is always done on the basis of an a priori homology analysis. The distribution criterion of homology-''homologous characters have identical or hierar chical distribution'' - is the basis of parsimony analysis. Because th is criterion also might fail in cases of genealogical reticulation or concerted homoplasy, character congruence is not a strict test but ano ther probabilistic criterion of homology. A synthetic approach is prop osed for phenotypic analysis with application of a priori criteria of homology. The resulting a priori probabilities of homology serve as cr iteria for selection and weighting of characters (very low = not selec ted/poor/mediocre/good/Dollo characters). After application of a parsi mony algorithm the final cladogram decides homology estimations. (C) 1 998 Academic Press.