Abstract

The study of the relationships between evolution and development lived a long eclipse after the triumph of experimental embryology and the rise of population genetics. Pere Alberch belongs to the series of biologists who aimed to integrate development within an incomplete evolutionary synthesis. He was well aware of the long history of the analogical tradition. Indeed, one of his earliest papers was a quantitative elaboration of the research program defended by S. J. Gould in his historically grounded Ontogeny and Phylogeny. Since then, von Baer, Agassiz, Haeckel, De Beer or Waddington became an admittedly recognized inspiration for his research. The history of EvoDevo is not a linear but a branching one. I will sketch the conceptual tree of EvoDevo through the answers given to some basic questions concerning the definition, phenomenology, explanation and methodology of the study of development and evolution: What is development and What is evolution? Which are the main developmental stages and how are they related to the history of life? Which are the causes of both development and evolution and how are they connected? How should we face all of these questions? Concerning definition, Alberch defined development as a dynamical system and evolution as constrained by the nature of the former. On the phenomenological side he was an advocate of the discontinuity of organic change, both in ontogeny (e. g. considering some developmental events as bifurcations) and in phylogeny (when defending the discrete character of morphospace). Regarding explanation Alberch was a mechanicist conceiving development as a dynamical and interactive system (focusing his research on the cellular and tissue aspects of pattern formation and morphogenesis ). Finally, concerning methodology Alberch became a great contributor for an integrative biology (being one of the pioneers in conciliating experimental embryology with phylogenetic research) as well as for the mathematization of biology (by using the tools developed with the study of complex systems). Departing from these answers to the posed questions, I will trace the phylogeny of the Alberch's ideas within the EvoDevo tree, finding his conceptual ancestors and distinguishing which of his contemporaries belonged to his species and which did not