WAGNER, G.; Yale Univ, New Haven: Rupert Riedl and the re-synthesis of Development and Evolution

The professional work of Rupert Riedl covers a lot of ground, spanning from comparative invertebrate anatomy and systematics to marine ecology, to evolutionary theory and philosophy of science as well as environmental ethics. In the context of this symposium the most relevant and interesting part of his work is the book �Die Ordnung des Lebendigen� which was published in 1975 in German and at Wiley in 1978 in English translation. In this book Rupert Riedl formulates his reaction to the then dominant Synthetic Theory of evolution. His main concern was that the emphasis of the ST on external causation due to population structure and adaptation to environmental conditions is too narrow to account for the pattern of morphological evolution. Whether this is in fact the case is still an unsettled question, but at least nowadays there is more openness towards the possibility that organismal traits act as constraints on evolutionary change. In this book Riedl developed a vision of how evolutionary theory can be supplemented to account for these phenomena. His idea was that in addition to selection and mutation we need to take into account so-called system�s properties that can lead to constraints on further evolutionary change. This theory is based on the insight that complex systems can not evolve if there are not some constraints on the production of phenotypic variation. This idea foreshadows current ideas about evolvability, like the No Free Lunch theorem of Wolpert and MacReady. Furthermore he foresaw that the key element for understanding morphological evolution is the evolution of development. Riedl�s work was thus the first grand synthesis of ideas about the need for a re-synthesis of developmental and evolutionary biology.