Abstract

Biology has always been in search of “syntheses.” Darwin’s Origin of Species (Darwin, On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. John Murray, London, 1859) gave maybe the first attempt to reconcile and think together various fields of biology such as biogeography, embryology, systematics, and paleontology. In the 1930s and 1940s, the Modern Synthesis emerged, based on the change of frequency of genes in a population by means of natural selection. The Synthesis unified different biological disciplines (Genetics, Cytology, Embryology, Systematics, Botany, Paleontology, Morphology) and emerged in different countries (USA, Britain, Germany) (Mayr and Provine, The evolutionary synthesis: Perspectives on the unification of biology. Harvard University Press, Cambridge, MA/London, 1980). However, as the Synthesis was ripening into an orthodox view on the process of organic evolution, several have complained of its “narrowing” and even of its “hardening” (Gould, Dimensions of Darwinism: Themes & counterthemes in twentieth-century evolutionary theory. Cambridge University Press/Éditions de la Maison des Sciences de l’Homme, Cambridge, New Rochelle/Paris, 1983). Moreover, several of its features were repeatedly challenged: especially the gradual approach to evolution and the use of microevolution as a proxy for macroevolution have been under fire. Major challenges include the neutralist view of mutation (Kimura) and the question of Punctuated Equilibria (Gould and Eldredge). More recently, new experimental data has complemented our views of the development of organisms (evo-devo) and the inheritance of characters (epigenetics). Some claim that the Modern Synthesis Theory of evolution should be rejected or simply revised or extended in the face of new biological data.