The national roots of evo–devo

Abstract

Thomas H. Huxley (1893), more embryologically inclined than his friend Charles Darwin, noted that ‘‘Evolution is not a speculation, but a fact; and it takes place by epigenesis’’. It is very interesting that he wrote ‘‘epigenesis,’’ and not ‘‘natural selection.’’ But Huxley was thinking on a different level of explanation than Darwin, and he saw that any change made in the anatomy of the organism had to come by changing its development. Around the same time as Huxley’s formulation of evolution, Roux (1894) wrote about the reformulation of embryology. He wrote that embryology was going to have to leave the ecological domain and enter into physiology. He predicted, however, that the newly acquired knowledge concerning the physiology of development would then return to evolutionary biology to bring a new approach, a ‘‘phylogenetic developmental mechanics’’ to the study of evolution. It took nearly 100 years to make good on Roux’s prophecy. During that century, the idea that one needed to understand development in order to explain evolutionary change was largely forgotten, as evolutionary biology emphasized intraspecies variation, allelic frequencies, and strictly genetic sources of variation. Traditions of comparative embryology, evolutionary morphology, and ecological embryology were marginalized as old-fashioned and unproductive. Evolutionary developmental biology represents many things, including a return to these questions that were abandoned. That is why historical reconstructions are especially important in case of evo– devo. Yet there are a few historically based and internationally approached studies in this new science. The present Special Issue was conceived as a venue to publish the papers delivered to the first and founding meeting of the European Society for Evolutionary Developmental Biology in the frames of the Symposium devoted to the national traditions in the history and pre-history of evo–devo. This symposium attempted to return to see what it was that these earlier scientists had been studying and how their ideas might be put into dialogue with our own. New disciplines demand a re-connection to the old, and, evolutionary developmental biology, a science deeply involved in questions of origin, needs to establish the conditions of its own ancestry. It cannot let other disciplines decide for it who its progenitors are. The papers published here do not pretend to cover the entire history of developmental biology in the national contexts. Rather they attract our attention to the selected episodes of this history illustrating the peculiarities of national scientific traditions or showing how the major international trends were converted into the national contexts. The Special Issue will appear in two parts. In the present, first, part we publish the papers dealing with Swedish, Russian, French and German contexts. Besides, a unique document, the autobiography of Julius Schaxel recently found in the archives is published here for the first time. The biography of this scientist, who can be seen as a link between German and Russian scientific cultures is an important source of historical evidences. The second part, which will appear next year, will concentrate on the developments in the Anglo-Saxon world. S. F. Gilbert (&) Department of Biology, Martin Research Laboratories, Swarthmore College, Swarthmore, PA 19081, USA e-mail: sgilber1@swarthmore.edu