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)

Koonin, in an article in this issue, claims that CRISPR–Cas systems are mechanisms for the inheritance of acquired adaptive characteristics, and that the operation of such systems comprises a “Lamarckian mode of evolution.” We argue that viewing the CRISPR–Cas mechanism as facilitating a form of “directed mutation” more accurately represents how the system behaves and the history of neoDarwinian thinking, and is to be preferred.

The article presents another of those ingenious mind, rebels to the yoke of religion, typical of the Italian Renaissance. Converted to Calvinism and therefore condemned to death by the Inquisition, Guglielmo Grataroli (1516-1568) became a defender of heterodox doctrine. His translation of a report of the Waldensian massacre in Calabria became part of the history of Protestant martyrs. He was the author of numerous treatises on various subjects, for which he widely used the works of Giovanni Michele Alberto da Carrara, (...) Antoine Mizauld and Gerolamo Cardano. The perfect correspondence of the topics discussed makes it probable that Giordano Bruno knew his writings. In particular, the De mutatione temporum, eiusque signis perpetuis may have inspired the De’ segni de’ tempi, a Bruno’s lost opera. This allows us to conjecture the content of the work with greater reliability. (shrink)

[1]. Liber V, De varietate legum humanarum et praesertim de odiosis --- [2]. Liber VI, de interpretatione, cessatione et mutatione legis humanae.

In 1913, the future psychologist and epistemologist Jean Piaget (1896-1980), then a seventeen-year-old naturalist, gave a talk criticizing 'the notion of the species according to the Mendelian school'. In it, he confounded Mendelism and mutationism, and misunderstood both. He attributed an environmental nature to the 'factors' postulated by Mendel's laws for inherited characteristics, and thought that mutations resulted from the appearance of a new environmental factor. Such misinterpretations are closely related to Piaget's assimilation of the Bergsonian critique of 'mechanistic' (...) science into his work in malacological taxonomy. (shrink)