In earlier work I have argued that the most substantial threat to scientific realism arises from the problem of unconceived alternatives: the repeated failure of past scientists and scientific communities to conceive of alternatives to extant scientific theories, even when such alternatives were both (1) well confirmed by the evidence available at the time and (2) sufficiently scientifically serious as to be later embraced by actual scientific communities. In this paper I explore Charles Darwin's development and defense of his 'pangenesis' (...) theory of inheritance and conclude that this particular historical example offers impressive support for the challenge posed to realism by this problem of unconceived alternatives. (shrink)

From its inception Darwinian evolutionary biology has been seen as having a problematic relationship of fact and theory. While the forging of the modern evolutionary synthesis resolved most of these issues for biologists, critics continue to argue that natural selection and common descent are “only theories.” Much of the confusion engendered by the “evolution wars” can be clarified by applying the concept of phenomena, inferred from fact, and explained by theories, thus locating where legitimate dissent may still exist. By setting (...) such analysis in the context of research traditions, it is possible to gain further insight into the complex interplay of facts, phenomena, and theories. Two case studies are explored to assess the value of such approaches, one from within evolutionary biology, the Baldwin effect, and one from outside, intelligent design. (shrink)

There is a pervasive contrast in the early natural history writings of the co-discoverers of natural selection, Alfred Russel Wallace and Charles Darwin. In his writings from South America and the Malay Archipelago (1848-1852, 1854-1862). Wallace consistently emphasized species and genera, and separated these descriptions from his rarer and briefer discussions of individual organisms. In contrast, Darwin's writings during the Beagle voyage (1831-1836) emphasized individual organisms, and mingled descriptions of individuals and groups. The contrast is explained by the different practices (...) of the two naturalists in the field. Wallace and Darwin went to the field with different educational experiences and social connections, constrained by different responsibilities and theoretical interests. These in turn resulted in different natural history practices; i.e., different habits and working routines in the field. Wallace's intense collecting activities aimed at a complete inventory of different species and their distributions at many localities. Darwin's less intense collecting practice focused on detailed observations of individual organisms. These different practices resulted in different material, textual and conceptual products. Placing natural history practices at the center of analysis reveals connections among these diverse products, and throws light on Wallace and Darwin's respective treatment of individuals and groups in natural history. In particular, this approach clarifies the relation between individuals and groups in Wallace's theory of natural selection, and provides an integrative starting point for further investigations of the broader social factors that shaped Victorian natural history practices and their scientific products. (shrink)

Es una opinión extendida que la teoría de la selección natural, tal como fue formulada originalmente por Darwin de manera “cualitativa”, ha sido reemplazada por una versión cuantitativa superior, brindada por la genética de poblaciones. En este artículo se discute contra esa tesis, sosteniendo en cambio que ambas teorías son complementarias, no sucesivas. Para ello, se introduce una línea de argumentación novedosa, que toma su inspiración en la crítica al “inductivismo estrecho” de Hempel. Se sostiene que los genetistas de poblaciones (...) serían incapaces de aplicar exitosamente su teoría sin hipótesis “ecológicas” preconcebidas, provenientes de la teoría darwiniana, que permitan particionar a la población en rasgos selectivamente relevantes. Se enfatiza además que la falla en notar este punto se debe a una mala comprensión de la estructura de la teoría darwiniana y de su ley o principio fundamental. A la luz de una mejor reconstrucción de dicho principio, se reexamina en mayor detalle la relación existente entre ambas teorías. (shrink)

References in Darwin’s Origin of Species to competition between units of selection at and above the level of individual organisms are enumerated. In many cases these references clearly speak of natural selection and do not support the view that Darwin thought selection only occurred at the level of the individual organism. Darwin did see organismal selection as the main process by which varieties were created but he also espoused what is here termed community and varietal selection. He saw no essential (...) difference between varieties and species and the references show that he also believed that selection could operate at the species level. (shrink)

An important historical relation that has hardly been addressed is the influence of Prosper Lucas's Treatise on Natural Inheritance on the development of Charles Darwin's concepts related to inheritance. In this article we trace this historical connection. Darwin read Lucas's Treatise in 1856. His reading coincided with many changes concerning his prior ideas on the transmission and expression of characters. We consider that this reading led him to propose a group of principles regarding prepotency, hereditary diseases, morbid tendencies and atavism; (...) following Lucas, he called these principles: laws of inheritance. (shrink)