Compelled by the Diagram: Thinking through C. H. Waddington’s Epigenetic Landscape

Abstract

Between 1940 and about 1960, Conrad Hal Waddington produced several illustrations to explain a concept central to his theories of developmental biology. The concept Waddington explained, the epigenetic landscape, was not based on settled science, and its implications were not easy to grasp. Unlike proponents of the most successful contemporary biological theory, Waddington was committed to including all biological phenomena–no matter how complex or unusual–in a single theoretical system. His intellectual style and use of images matched his ambition. Waddington used compelling images to get his readers to engage with and work through his theories. His images used a shifting, even contradictory, set of metaphors and analogical models, from train yards to crafted topological surfaces. Through an analysis of Waddington’s images and theories, I show that taking a close look at what scientific images show and how they show it is important for the historiography of science. Images can be effective at drawing viewers in, confounding them, and prodding them to ask questions; this is one reason images are necessary for science.