The Early Cambrian metazoan radiation involved a period of lower metazoan evolution coupled with a relatively abrupt diversification of body types, many now extinct, during the Cambrian. This history implies a sequence of changes in genetic control or morphological pattern formation to encode the sequence of novel architectures. This project will investigate the relations between (1) the indications of early body types furnished by trace and body fossils and the implied evolution of pattern- formation capabilities of the genome; and (2) the radiation of (chiefly segmented) body types of higher invertebrates and the implied pattern of change in the tiers of genetic-regulatory control.
