Homology and misdirection

Abstract

Hennig (1966) recognized symplesiomorphies as homologies, and that view is logically correct under the concept of homology (homogeny) prevalent among evolutionists since 1870. Nelson and Platnick (1981) instead wanted homology to exclude symplesiomorphies for reasons that they never made clear but which certainly included opposition to Hennig. They and some of their followers, most recently Platnick (2013) and Brower and de Pinna (2013), have continued to advocate that anti-Hennigian position, often under the slogan "homology equals synapomorphy," while ironically passing themselves off as cladists and often using ambiguous or falsified citations to pretend that legitimate phylogeneticists think likewise. Such authors have seldom shown much concern for accuracy or logic, with the result that a great deal of print has been wasted. Those problems can be avoided simply by maintaining a Hennigian view and so discarding the purported equivalence of homology and synapomorphy.