Abstract

The Modern Synthesis has been receiving bad press for some time now. Back in 1983, in an article entitled “The Hardening of the Modern Synthesis” Stephen Jay Gould criticized the way the Modern Synthesis had developed since its inception in the 1930s and early 1940s (Gould 1983). Back then, those who would later become known as ‘architects’ of the synthesis were united in their call for explaining evolution at all levels in terms of causation at one level: genetics. What drove changes in gene frequency remained an open question. It could be mainly selection, or drift, or some (other) form of constraint. But in the two decades that followed, the synthesis underwent a major change. By the late 1940s the synthesis had ‘hardened’ around adaptationism, according to Gould. Influential contributors like Dobzhansky, Simpson and Wright had increasingly expressed adaptationist views in the later editions of their landmark books. Not because evidence had piled up, showing that selection was in fact pervasive. Instead, Gould argued, adaptationist tendencies had been preserved by some kind of cultural inertia, and were now being revived. “Certain ‘national styles’ persisted from the eighteenth century, through Darwin’s era, and into our own time. Views on adaptation provide a good example” (Gould 1983). Gould did not just argue that some form of adaptationism had resurfaced. He became well-known for his efforts to intervene on this status quo by attempting to make evolutionary biology more ‘pluralistic’. In collaborative work with Richard Lewontin (Gould and Lewontin 1979), Elisabeth Vrba (Gould and Vrba 1982; Vrba and Gould 1986) and Niles Eldredge (Eldredge and Gould 1972; Gould and Eldredge 1977) he criticized the synthesis for its adaptationism and its lack of appreciation for hierarchical perspectives. Gould exerted his influence in a different way as well. Together with Eldredge, he had facsimiles reprinted of the first editions of two books that had shaped synthesis, but with their own critical introductions (Eldredge 1982; Gould 1982). Dobzhansky’s Genetics and the Origin of Species and Mayr’s Systematics and the Origin of Species appeared as reprints in the ‘Columbia Classics in Evolution’ series, sending an unambiguous message to the readers: these are foundational works, but they have been superseded. In the summer of 2008, some 25 years after Gould made his point about the hardening of the Modern Synthesis, a group of sixteen biologists and philosophers gathered at the Konrad Lorenz Institute for Evolution and Cognition Research (KLI) near Vienna, Austria, to discuss cutting-edge research that reaches beyond the synthesis framework. Before it even started, this workshop on the ‘Extended Synthesis’ had already attracted a fair share of attention in the blogosphere and had resulted in a news feature in Science (Pennisi 2008). After the meeting, Nature weighed in on the matter (Whitfield 2008). The results of over 3 days of presentations and extensive discussion have now been published as Evolution—The Extended Synthesis. 1 The publication of this collection of sixteen essays is accompanied by the republication of Julian Huxley’s Evolution: The Modern Synthesis; the book that introduced the term ‘Modern Synthesis’. Both books are introduced by the organizers of the KLI workshop, Massimo Pigliucci and Gerd Müller. Like Gould and Eldredge before them, Pigliucci and Müller did not reissue one of the canons of the Modern Synthesis without giving the readers some ‘guidance’. Starting with the cover, the editors proclaim boldly that this is ‘the definitive edition’ of Huxley’s book. In a new foreword, they sketch the context in which the book was written and assess some of its features. They voice some mild criticism of alleged ‘adaptationism’. But their tone is different from that of Gould and Eldredge. Pigliucci and Müller praise Huxley for his pluralistic outlook, which has again become essential in the forging of an Extended Synthesis. That makes Huxley’s book more than just an interesting but obsolete classic. Instead, it can teach valuable lessons about how to ‘soften up’ a synthesis that has become hardened over time.