According to a classical narrative, early geneticists, failing to see how Mendelism provides the missing pieces of Darwin’s theory, rejected gradual changes and advocated an implausible yet briefly popular view of evolution-by-mutation; after decades of delay (in which synthesis was prevented by personal conflicts, disciplinary rivalries, and anti-Darwinian animus), Darwinism emerged on a new Mendelian basis. Based on the works of four influential early geneticists – Bateson, de Vries, Morgan and Punnett –, and drawing on recent scholarship, we offer an (...) alternative that turns the classical view on its head. For early geneticists, embracing discrete inheritance and the mutation theory (for the origin of hereditary variation) did not entail rejection of selection, but rejection of Darwin’s non-Mendelian views of heredity and variation, his doctrine of natura non facit saltum, and his conception of “natural selection” as a creative force that shapes features out of masses of infinitesimal differences. We find no evidence of a delay in synthesizing mutation, rules of discrete inheritance, and selection in a Mendelian-Mutationist Synthesis. Instead, before 1918, early geneticists had conceptualized allelic selection, the Hardy–Weinberg equilibrium, the evolution of a quantitative trait under selection, the probability of fixation of a new mutation, and other key innovations. Contemporary evolutionary thinking seems closer to their more ecumenical view than to the restrictive mid-twentieth-century consensus known as the Modern Synthesis. (shrink)

Hugo de Vries (1848–1935) would without doubt turn in his grave if he could be told about the various perspectives from which historians have studied his ideas and works. His would not be an exceptional case, of course, for many before and after him have fallen victim to the irony of history. Still, I am inclined to grant de Vries that he would have some reason for his distress, for the irony has hit him particularly hard. In 1922, de Vries (...) was invited to attend the Mendel centennial celebrations at Brünn (Brno). He declined the invitation, suspecting, among other things, that the tenor of the commemoration would be pro-Mendel and anti-Darwin, and he heartily refused to share in either sentiment. Now contrast this with de Vries' imputed role in the historiography of genetics and evolutionary theory as ‘rediscoverer’ of Mendelism and as co-executor of the ‘eclipse of Darwinism’, and the irony will be clear. (shrink)

This article discusses the contribution to evolutionary theory of Leonard Darwin, the eighth child of Charles Darwin. By analysing the correspondence Leonard Darwin maintained with Ronald Aylmer Fisher in conjunction with an assessment of his books and other written works between the 1910s and 1930s, this article argues for a more prominent role played by him than the previously recognised in the literature as an informal mentor of Fisher. The paper discusses Leonard’s efforts to amalgamate Mendelism with both Eugenics and (...) Darwinism in order for the first to base their policies on new scientific developments and to help the second in finding a target for natural selection. Without a formal qualification in biological sciences and as such mistrusted by some “formal” scientists, Leonard Darwin engaged with key themes of Darwinism such as mimicry, the role of mutations on speciation and the process of genetic variability, arriving at important conclusions concerning the usefulness of Mendelian genetics for his father’s theory. (shrink)