Evolving Form and Function: Fossils and Development Proceedings of a symposium honoring Adolf Seilacher for his contributions to paleontology, in celebration of his 80th birthday

Adolf Seilacher’s major contribution to our understanding of the evolution of morphology has been to emphasize that function is an important, but far from complete, explanation of organic form. Recognizing the influence of phylogeny and architecture in addition to adaptation, Seilacher formalized this realization in 1970 as “Konstruktions–Morphologie” (constructional morphology). This “triangular” approach was very influential at a time when there was little interest in constraints on the evolution of form. In 1990, 20 years on, Seilacher expanded the triangle to include an environmental dimension; although this cannot be measured directly, it is important conceptually. He renamed the investigation of form “morphodynamics.” Seilacher highlighted the significant role of fabricational noise, including self-organization, intercalational hierarchies and morphogenetic countdowns, in determining morphology. He applied the methods of constructional morphology to a range of organisms, from vendobionts to barnacles, clams to crinoids. Seilacher’s results are illuminated by his unique explanatory terminology and the iconography of his line drawings.