Systematic Zoology: Slicing the Gordian Knot with Ockham's Razor

Systematic zoology has undergone a revolution during the past25 years. A major step was in the formulation of an explicitand objective methodology for determining phylogenetic relationshipsthat results in testable hypotheses. The methodology of phylogeneticsystematics has spawned vicariance biogeography and is applicablenot only to traditional morphological characters but to newkinds of systematic characters. Innovative biochemical, cytogenetic,and developmental approaches to phylogenetic relationships havebroadened the scope of systematic zoology. This diversity increasesthe potential for generating and testing hypotheses of phylogeneticrelationships and temporal evolution.