Spring 2026 Colloquium - Gregory Radick

Title: Salience traditions as a theme in the pedagogical epistemology of science: The case of genetics

 

Abstract: Since Kuhn, philosophers of science have appreciated the role that exemplar-based reasoning plays in organizing a body of scientific knowledge as well as in organizing the research and teaching efforts of the scientific community that emerges around that knowledge. As Kuhn emphasized, it’s in the conservative nature of exemplar extension that scientific problems which more obviously lend themselves to solution via modest adjustments in the existing reasoning skills, apparatus, presuppositions etc. attract attention, with problems lying outside that domain regarded as uninteresting (except by mavericks, whose status is underscored precisely by that sort of interest), and with some unassimilable phenomena dropping away from scientific attention entirely (“Kuhn loss”).  The result is that choices made at the start of inquiry about what to emphasize and what to marginalize – or even outright ignore – can have ramifying consequences for how a science develops.

For over a century, what has been made salient to the beginning student in genetics are the binary traits which Gregor Mendel studied in his crossbred peas, the patterns of dominance and recessiveness that he discovered by tracking those binaries, and the atom-like entity – the gene – which, according to textbooks anyway, Mendel introduced in order to explain those patterns. Unquestionably, a curriculum that anchors students in elementary Mendelism can be highly successful on its own terms, step-by-step guiding students into genetic problem-solving as the gradual extension of Mendel’s reasoning to ever more complex cases. But it does so at the price of having students imprint on basic examples of inheritance in which – unlike the vast majority of inherited traits in the real world – nothing matters to explaining why they are as they are except the combination and recombination of genetic variants or “genotypes.” What is made salient in elementary Mendelism is, then, scientifically misleading. Many have long worried that it might be even worse than that, in that elementary Mendelism seems also to bring with it a determinism about genes that can shade into essentialism about people, related to an incuriosity about real-world variability and the multifactorial causation that brings it about.

Drawing on my recent book Disputed Inheritance: The Battle over Mendel and the Future of Biology (U. Chicago, 2023), I’ll describe how historical inquiry into the early twentieth-century debate over Mendel – and in particular, into the work of the leading critic of emerging Mendelism, W. F. R. Weldon (1860-1906) – opened up the historical possibility that genetics as a body of knowledge might have had an alternative, traits-are-modifiable-in-environments salience pattern. I’ll then look at how that historical possibility in turn prompted a counterfactual or “what-if?” question: what difference would it have made to genetics and society had genetic knowledge been organized not in line with Mendelian emphases but with Weldonian ones? I’ll also discuss my attempt to answer that counterfactual question by way of a novel classroom experiment, reflecting on the potential significance of the experiment for the history and philosophy of science, for genetics and its pedagogy, and for the disruption of salience traditions in science more widely.