Physics matters less than we once thought to the making of Mendel. But it matters more than we tend to recognize to the making of Mendelism. This paper charts the variety of ways in which diverse kinds of physics impinged upon the Galtonian tradition which formed Mendelism’s matrix. The work of three Galtonians in particular is considered: Francis Galton himself, W. F. R. Weldon and William Bateson. One aim is to suggest that tracking influence from physics can bring into focus (...) important but now little-remembered flexibilities in the Galtonian tradition. Another is to show by example why generalizations about what happens when ‘physics’ meets ‘biology’ require caution. Even for a single research tradition in Britain in the decades around 1900, these categories were large, containing multitudes. (shrink)

Advocates of “Mendelism” early on stressed the usefulness of Mendelian principles for breeders. Ever since, that usefulness—and the favourable opinion of Mendelism it supposedly engendered among breeders—has featured in explanations of the rapid rise of Mendelian genetics. An important counter-tradition of commentary, however, has emphasized the ways in which early Mendelian theory in fact fell short of breeders’ needs. Attention to intellectual property, narrowly and broadly construed, makes possible an approach that takes both the tradition and the counter-tradition seriously, by (...) enabling a more complete description of the theory-reality shortfall and a better understanding of how changing practices, on and off the Mendelians’ experimental farms, functioned to render that shortfall unproblematic. In the case of plant breeding in Britain, a perennial source of lost profits and disputes over ownership was the appearance of individual plants departing from their varietal types—so-called “rogues.” Mendelian plant varieties acquired a reputation for being rogue-free, and so for demonstrating the correctness of Mendelian principles , at a time when Mendelians were gradually taking control of the means for distributing their varieties. Mendelian breeders protected their products physically from rogue-inducing contamination in such a way that when rogues did appear, the default explanation—that contamination had somehow occurred—ensured that there was no threat to Mendelian principles. (shrink)

This paper argues that our modern concept of biological heredity was first clearly introduced in a theoretical and practical setting by the generation of French physicians that were active between 1810 and 1830. It describes how from a traditional focus on hereditary transmission of disease, influential French medical men like Esquirol, Fodéré, Piorry, Lévy, moved towards considering heredity a central concept for the conception of the human bodily frame, and its set of physical and moral dispositions. The notion of heredity (...) as a natural force, with a wide ranging capabilities of transmitting differentially both fundamental and accidental characters was generalized by that generation of physicians with the help of contemporary naturalists and physiologists. By 1830 the term hérédité was widespread, and it shared the explanatory and semantic qualities of traditional medical concepts like constitution and temperament. An analysis is given of the main developments that led to the conception of biological (including human) bodies as consisting of a layered, hierarchical organization of characters, differentially affected by the laws of conservation (Heredity) and change (Inneity, Variation). The mid-century work of the French physician Prosper Lucas, Traité Philosophique et Physiologique de L'Hérédité Naturelle, is shown to be the culmination of the efforts of several generations of French physicians towards having a feasible, complexly structured notion of how heredity works. (shrink)