Evolutionary novelty: a philosophical and historical investigation

Abstract

Evolutionary novelty, the origin of new characters such as the turtle shell or the flower, is a fundamental problem for an evolutionary view of life. Accordingly, it is a central research topic in contemporary biology involving input from several biological disciplines and explanations at several levels of organization. As such it raises questions relative to scientific collaboration and multi-level explanations. Novelty is also involved in theoretical debates in evolutionary biology. It has been appropriated by evo-devo, a scientific synthesis linking research on evolution and development. Thanks to its focus on development, evo-devo claims to explain the mechanistic origin of novelties as new forms, while the Modern Synthesis can only provide statistical explanation of evolutionary change. The origin of an evolutionary novelty is a historical emergence of a new character involving form and function. I focus on three neglected dimensions of the problem of novelty, the functional-historical approach to the problem, research on novelty in the Modern Synthesis era and novelty in plants. I compare the evo-devo approach to novelty to a functional-historical approach of novelty. I focus on its origin in Darwin and its presence in the Modern Synthesis. The comparison of the two approaches reveals distance between conceptual frameworks and proximity in explanatory practices. This is partly related to unwarranted conceptual opposition. In particular, I list several ways of distinguishing novelty and adaptation, some of which are not conceptually sound. I then focus on the relation between novelty and adaptation in the Modern Synthesis era, and on the relation of novelty to other fundamental biological problems (speciation, origin of higher taxa, complexity). Pushing this approach further, I challenge the view that the Modern Synthesis excluded development and reached a hardened consensus. Finally, I analyse how Günter Wagner’s developmental theory of novelty applies to novelties in plant.