An Empirical Evaluation of the Use of the Ontogeny Polarization Criterion in Phylogenetic Inference

Abstract

The ontogeny character polarization criterion was empirically evaluated relative to the outgroup criterion using the salamander genus Ambystoma. The ontogeny criterion produced a single most-parsimonious tree which was equally or better-resolved than the four most-parsimonious trees produced by the outgroup criterion. Using the consensus tree to represent the outgroup results, the two criteria derive essentially the same topology. Thus, in comparing topological similarity, level of resolution, and degree of ambiguity, the ontogeny criterion performs as well as or better than does the outgroup criterion in resolving the relationships of this study group. The superior performance of the ontogeny criterion appears to be due to its robustness to the effects of paedomorphic characters as long as those characters do not predominate in the data set. This robustness suggests that the requirements for successful application of the ontogeny criterion may be widely met in nature and that the criterion, therefore, may be useful in resolving the relationships of taxa in which outgroup analysis is problematical.