THEORIES AND METHODS IN DIFFERENT APPROACHES TO PHYLOGENETIC SYSTEMATICS

Abstract

Abstract— Systematic techniques may be viewed as symbolic languages which have both surface structure (measures of descriptive adequacy) and deep structure (measures of explanatory adequacy). Phylogenetic systematics is not theory‐neutral because its deep structure embodies evolutionary assumptions. Pattern cladistics stands in relationship to phylogenetic systematics as a part to a whole and is indistinguishable from phylogenetic systematics unless an artificial dichotomy between surface structure and deep structure is maintained. Direct observation of ontogeny as a means of polarizing characters also stands as a part to a whole relative to outgroup comparisons. Direct observation of ontogeny does not resolve any cases that outgroup comparison fails to resolve, and outgroup comparison does resolve some cases where direct observation fails. © 1985 The Willi Hennig Society