Evolutionary Morphology, Innovation, and the Synthesis of Evolution and Development

One foundational question in contemporary biology is how to integrate evolution and development. The emerging synthesis (evolutionary developmental biology or evo-devo) requires a meshing of disciplines, concepts, and explanations (inter alia) that have been developed largely in independence over the past century. The nature of the hoped for synthesis is not wholly agreed upon due to divergent viewpoints resulting from this disciplinary independence and, consequently, the mechanics for accomplishing the task are not clearly specified. This paper utilizes historical investigation for philosophical purposes in order to explore the question of synthesizing evolutionary and developmental biology. In the attempt to comprehend the present separation between evolution and development much attention has been paid to the split between genetics and embryology in the early part of the century with its codification in the exclusion of embryology from the Modern Synthesis. This encourages a characterization of "evo-devo" as the integration of developmental genetics with Neo-Darwinism. But there is a largely untold story about the significance of morphology and comparative anatomy (also minimized in the Modern Synthesis). I will attempt to reconstruct part of this story, focusing on the rebirth of functional (and evolutionary) morphology after the 1950s. Functional morphology is critical for understanding the development of a concept central to "evo-devo", evolutionary innovation. Understanding the story about morphology and innovation reveals a different conception of the foundational problem, providing alternative ways of conceptualizing the "evo" and the "devo" to be synthesized