Types and the Geoffroy—Cuvier Debates: A Crossroads in Evolutionary Morphology

Abstract

Pre-Darwinian 18th- and 19th-century morphologists used several interrelated terms and concepts to explain morphological similarities among different organisms and how groups of organisms could be united on the basis of common anatomical design: the Type (Typus),the Archetype, unity of type and unity of plan. Embryological criteria became increasingly important in this quest, but embryology too was typological. The eventual acceptance that all animal life had a common origin and that animal development was based on similar embryological processes, produced the evolutionary morphology and evolutionary embryology of the late 19th century, and led to the evolutionary developmental biology of the 20th.

‘What is the essence of life — organization or activity?’ Russell, 1916, p. v