Congruence and language

Abstract Knowledge claims in comparative biology are interpretations/explanations (propositions) of facts. These facts help us to discover the interrelationships amongst taxa and areas. Relationships are information disseminated in the form of language. Propositions, in cladistics and cladistic biogeography, are based on congruence. In a cladogram, for instance, congruent apomorphic character­states form a synapomorphy. Synapomorphies may be treated as topographical units that depict evolutionary relationships (synchrony) or evolutionary events (diachrony). In cladistic biogeographical and systematic theory, synchronic and diachronic statements of relationships conflict in their interpretation of non­congruence. Comparative biology needs a meaningful language, for without it conflict becomes congruence and non­information becomes knowledge.