MODEL SYSTEMS VERSUS OUTGROUPS - ALTERNATIVE APPROACHES TO THE STUDY OF HEAD DEVELOPMENT AND EVOLUTION

There is widespread recognition of a recent coming together of develop mental and evolutionary biology in the study of problems of mutual int erest. Contemporary studies into the development and evolution of the head largely comprise two parallel approaches, or research strategies: the model systems approach and the comparative approach. The two stra tegies share the same general goal-greater understanding of cranial de velopment and evolution-but typically emphasize different problems, as k different questions, and employ different methods, reflecting the co ntrasting backgrounds and biases of each group of investigators; there has been relatively little true synthesis. Each strategy is making im portant and valid contributions, but both have limitations. Resolution . of many fundamental and long-standing problems in cranial developmen t and evolution will require a combined approach that incorporates the technical and conceptual strengths of each discipline.