Experimental strategies in evolutionary embryology

Abstract

The combination of developmental and evolutionary approaches to morphology constitutes a new field of research, here termed evolutionary embryology. At present, the field is characterized by a strong prevalence of theoretical concepts over empirical investigations. This paper analyzes the possible strategies for experimental approaches to provide a broader empirical foundation for the existing concepts. Five domains of development-recapitulation, timing, interaction, thresholds, and plasticity-are investigated with regard to their role in morphological evolution and their accessibility for experimentation. It is argued that the temporal, spatial, and functional dissociabilities of interactive developmental systems, as well astheir quantitative and integrative properties, constitute the main targets of experimentation. Further itis emphasized that the comparative method represents the fundamental conceptual tool for evolutionary approaches to embryology. © 1991 by the American Society of Zoologists.