Cladograms, Phylogenetic Trees, and Hypothesis Testing

Abstract

One criticism expressed of cladistic analysis is that it is an eminently logical method but one that is based on biologically unacceptable assumptions or axioms. Critics contend that all speciation is dichotomous or that evolutionary rates are always equal (or always unequal). The author argues that no such assumptions are required by cladistics, that the belief that they are required is the result of a failure to distinguish between cladograms and phylogenetic trees, and that it is conventional phylogeny reconstruction, operating with phylogenetic trees rather than cladograms, that is unacceptable (because it relies on the absence of data to reject hypotheses).