Hennig developed the cladistic method on the basis of the assumption that new species originate by the splitting of a stem species into two daughter species, hence on the principle of dichotomy: The parental species disappears with the birth of the two daughter species. He saw the origin of new higher taxa in an equivalent manner as a dichotomous process. Much research of the last 50 years has indicated, however, that budding is a far more frequent way of originating new taxa than is splitting. When a new species originates by means of peripatric speciation, this has no effect on the parental species from which the neospecies has budded off. However, by Hennig's criteria, a species which has given rise to a new species by budding thereby becomes paraphyletic and has to be removed from the classification, even though it has not been affected by the budding event. The same alignment pertains to higher taxa, most of which evidently originated by the budding off of an enterprising new species that was successful in a new niche or adaptive zone. The parental taxon continued to flourish unchanged in its traditional niche, but it has become paraphyletic by cladistic definition and must be excluded from the classification. It is now fully evident that the proposal to disqualify paraphyletic groups from recognition in classifications is not only impractical and destructive but scientifically untenable.--Ernst Mayr and Peter Ashlock 1991, Principles of Systematic Zoology, 2nd. Ed.

Below are two diagrams to illustrate Mayr and Ashlock's point. Both diagrams are based on mtDNA data from the same paper. As one can see, S. hammondii did not become extinct when S. bombifrons evolved. S. hammondii survived, unaltered by the speciation event giving rise to S. bombifrons, through peripatric speciation. Likewise, the family Pelobatidae did not become extinct when some member of the ancestral family gave rise to the family Pelodytidae. mtDNA data therefore shows that Hennig was wrong. Not only do species taxa not become extinct when new species evolve, higher taxa too follow the same pattern of evolution.

The Hennigians nevertheless simply ignore the fact that Hennig was wrong. The Hennigians (aka cladists) continue their crusade to eliminate paraphyly, even though Rober L. Carroll (1988 Vertebrate Paleontology and Evolution, p. 13) points out that paraphyletic groups are the inevitable result of the process of evolution. In the paper by Garcia-Paris et al., they sought to eliminate paraphyly by removing some members of the Pelobatidae and placing them in the family Scaphiopodidae. Such a proposal is both destructive and scientifically untenable, as Mayr and Ashlock pointed out. Such a proposal also creates two different families that are morphologically very similar to one another and their common ancestor, while obscuring the close relationship between the "scaphiopodids" and pelobatids. Their proposal also means that the common ancestor of the pelobatids, "scaphipodids" and pelodytids cannot be classified in any of these three families. A sane, taxonomically stable and scientifically tenable alternative is to continue to recognize the Pelobatidae as a paraphyletic taxon while maintaining the Pelodytidae as a valid taxon.

A great deal of taxonomic chaos being generated by the cladists' destructive and scientifically untenable intolerance of paraphyletic taxa can be avoided if they only realize that Hennig was simply wrong about evolution.

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