As has been frequently remarked, Charles Darwin often used narratives to explain evolutionary change, as when he traced how the eye might have evolved from a patch of light-sensitive skin into a complex optical instrument. But narrative played a more fundamental role for Darwin, and one far less well-understood: narrative fundamentally informed the concepts out of which Darwin constructed his science. It is straightforward enough that Darwin's two most important conceptual innovations—natural and sexual selection—are narrative in structure. But Darwin also repeatedly took concepts that other natural historians had conceived as expressing static properties and reconceptualized them through a narrative lens. Taxonomists, for example, typically conceived affinity as a static relation of morphological similarity; Darwin reconceived affinity as a historicized relation of genealogical connection. He also took what other naturalists conceived as invariant laws of nature and reconceived them in narrative terms, as when he argued that Baer’s “laws” of unity of structure and unity of plan in embryology should be understood as consequences of processes of historical change. Darwin even offered narrativized reconceptualizations of sex, beauty, and morality. Finally, narrative structured the standards by which Darwin conceived that scientific hypotheses should be evaluated. In the place of John Herschel’s notion that a phenomenon is explained by breaking it into its component parts and offering a vera causa (true cause) for each part, Darwin proposed that explanations be evaluated holistically for how they made sense of a wide array of disparate phenomena. Narrative, in short, suffused Darwin’s science.
