Recent discussion of mechanism has suggested new approaches to several issues in the philosophy of science, including theory structure, causal explanation, and reductionism. Here, I apply what I take to be the fruits of the 'new mechanical philosophy' to an analysis of a contemporary debate in evolutionary biology about the role of natural selection in speciation. Traditional accounts of that debate focus on the geographic context of genetic divergence--namely, whether divergence in the absence of geographic isolation is possible (or significant). (...) Those accounts are at best incomplete, I argue, because they ignore the mechanisms producing divergence and miss what is at stake in the biological debate. I argue that the biological debate instead concerns the scope of particular speciation mechanisms which assign different roles to natural selection at various stages of divergence. The upshot is a new interpretation of the crux of that debate--namely, whether divergence with gene flow is possible (or significant) and whether the isolating mechanisms producing it are adaptive. (shrink)

Historians and philosophers of science agree that Darwin had an understanding of species which led to a workable theory of their origins. To Darwin species did not differ essentially from ‘varieties’ within species, but were distinguishable in that they had developed gaps in formerly continuous morphological variation. Similar ideas can be defended today after updating them with modern population genetics. Why then, in the 1930s and 1940s, did Dobzhansky, Mayr and others argue that Darwin failed to understand species and speciation? (...) Mayr and Dobzhansky argued that reproductively isolated species were more distinct and ‘real’ than Darwin had proposed. Believing species to be inherently cohesive, Mayr inferred that speciation normally required geographic isolation, an argument that he believed, incorrectly, Darwin had failed to appreciate. Also, before the sociobiology revolution of the 1960s and 1970s, biologists often argued that traits beneficial to whole populations would spread. Reproductive isolation was thus seen as an adaptive trait to prevent disintegration of species. Finally, molecular genetic markers did not exist, and so a presumed biological function of species, reproductive isolation, seemed to delimit cryptic species better than character-based criteria like Darwin’s. Today, abundant genetic markers are available and widely used to delimit species, for example using assignment tests: genetics has replaced a Darwinian reliance on morphology for detecting gaps between species. In the 150th anniversary of The Origin of Species , we appear to be returning to more Darwinian views on species, and to a fuller appreciation of what Darwin meant. (shrink)

Alexander von Humboldt’s depictions of mountain vegetation are among the most iconic nineteenth century illustrations in the biological sciences. Here we analyse the contemporary context and empirical data for all these depictions, namely the _Tableau physique des Andes_ (1803, 1807), the _Geographiae plantarum lineamenta_ (1815), the _Tableau physique des Îles Canaries_ (1817), and the _Esquisse de la Géographie des plantes dans les Andes de Quito_ (1824/1825). We show that the Tableau physique des Andes does not reflect Humboldt and Bonpland’s field (...) data and presents a flawed depiction of plant occurrences and vertical succession of vegetation belts, arising from Humboldt’s misreading of La Condamine’s description (1751). Humboldt's 1815 depiction, by contrast, shows a distribution of high-vegetation belts that is consistent with La Condamine’s description, while the 1824 depiction drops innovations made in 1815 and returns to simply showing numerous species’ names, thus not applying Humboldt’s own earlier zonation framework. Our analysis of contemporary reactions to Humboldt’s TPA includes Francis Hall’s posthumously published 1834 illustration of Andean plant zonation near Quito and Humboldt’s reaction to Hall’s critique. Throughout his work on plant geography, Humboldt disregarded some of his own observations, or confused them. At stake was his reputation as an innovator in the field of plant geography and a discoverer of the sequence of high-elevation vegetation belts on the world’s mountains. (shrink)

This essay examines how Indo-Pacific indigenous plant names went from being viewed as instruments of botanical fieldwork, to being seen primarily as currency in anthropological studies. I trace this attitude to Alexander von Humboldt, who differentiated between indigenous phytonyms with merely local relevance to be used as philological data, and universally applicable Latin plant names. This way of using indigenous plant names underwrote a chauvinistic reading of cultural difference, and was therefore especially attractive to commentators lacking acquaintance with any indigenous (...) language or culture. When New Zealand anthropologists embraced this role for Māori phytonyms in the 1890s, however, they did so possessed of a relatively in-depth understanding of Māori culture and the Māori language. This discussion has three primary aims: to illuminate nineteenth-century scholarly engagements with Indo-Pacific plant classifications, in contrast to a prevailing historiographical emphasis on European disregard for this subject; to analyse how indigenous phytonyms acted as ‘boundary objects’ interfacing between cultures and disciplines; and to illustrate the politics of scientific disciplinarity in a colonial context. (shrink)

Darwin is well known for his wondrously ambiguous rhetoric. The author who used an ‘entangled bank’ as his metaphor for Nature and its complex relationships built up the substance of his text from a corresponding entanglement of unresolved theoretical relations. Ambiguous positions, arguments that seem to fold in on themselves, vacillations, contradictions, and pluralities of explanation suffuse Darwin's science and its constituent metascience. The Origin abounds in ambiguities with regard to the technical features of evolutionary biology. But the domain of (...) ambiguity I wish to address is Darwin's metaphysical stance. I want to approach the question of Darwin and secularization through what might be called the trope of ambiguity. My principle concern is with the origins of that ambiguity. These lie in the conflicting cultural and ideological resources Darwin used to construct the theory of natural selection. (shrink)

Darwin begins On the Origin of Species by asking the reader to “reflect on the vast diversity of the plants and animals which have been cultivated” (1859, p. 7); almost five-hundred pages later, he closes by having the reader consider the “endless forms most beautiful and wonderful” that have evolved (1859, p. 490). Darwin contemplates diversity throughout the Origin and presents the principle of divergence as a way to explain it. Darwin formulated the principle of divergence around 1857 (Browne 1980), (...) at which point he began replacing his previous view of “limited perfect adaptedness” with a view of relative adaptedness (Ospovat 1981; Burian 1983). Proponents of perfect adaptedness, such as Paley and .. (shrink)

In 1749, Linnaeus presided over the dissertation "Oeconomia Naturae," which argued that each creature plays an important and particular role in nature 's economy. This phrase should be familiar to readers of Darwin, for he claims in the Origin that "all organic beings are striving, it may be said, to seize on each place in the economy of nature." Many scholars have discussed the influence of political economy on Darwin's ideas. In this paper, I take a different tack, showing that (...) Darwin's idea of an economy of nature stemmed from the views of earlier naturalists like Linnaeus and Lyell. I argue, in the first section of the paper, that Linnaeus' idea of oeconomia naturae is derived from the idea of the animal economy, and that his idea of politia naturae is an extension of the idea of a politia civitatis. In the second part, I explore the use of the concept of stations in the work of De Candolle and Lyell – the precursor to Darwin's concept of places. I show in the third part of the paper that the idea of places in an economy of nature is employed by Darwin at many key points in his thinking: his discussion of the Galapagos birds, his reading of Malthus, etc. Finally, in the last section, I demonstrate that the idea of a place in nature 's economy is essential to Darwin's account of divergence. To tell his famous story of divergence and adaptation, Darwin needed the economy of nature. (shrink)

The paper characterizes Darwin's theory, providing a synthesis of recent historical investigations in this area. Darwin's reading of Malthus led him to appreciate the importance of population pressures, and subsequently of natural selection, with the help of the wedge metaphor. But, in itself, natural selection did not furnish an adequate account of the origin of species, for which a principle of divergence was needed. Initially, Darwin attributed this to geographical isolation, but later, following his work on barnacles which underscored the (...) significance of variation, and arising from his work on botanical arithmetic, he supposed that diversity allowed more places to be occupied in a given region. So isolation was not regarded as essential. Large regions with intense competition, and with ample variation spread by blending, would facilitate speciation. The notion of place was different from niche, and it is questioned whether Darwin's views on ecology were as modern as is commonly supposed. Two notions of struggle are found in Darwin's theory; and three notions of variation. Criticisms of his theory led him to emphasize the importance of variation over a range of forms. Hence the theory was populational rather than typological. The theory required a Lamarckian notion of inheritable changes initiated by the environment as a source of variation. Also, Darwin deployed a use/habit theory; and the notion of sexual selection. Selection normally acted at the level of the individual, though kin selection was possible. Group selection was hinted at for man. Darwin's thinking (and also the exposition of his theory) was generally guided by the domestic-organism analogy, which satisfied his methodological requirement of a vera causa principle. (shrink)

We performed a critical review of the historiographical studies on biogeography. We began with the pioneering works of Augustin and Alphonse de Candolle. Then, we analyzed the historical accounts of biogeography developed by (1) Martin Fichman and his history on the extensionism-permanentism debate; (2) Gareth Nelson and his critique of the Neo-Darwinian historiography of biogeography; (3) Ernst Mayr, with his dispersalist viewpoint; (4) Alan Richardson, who wrote a microhistory on the biogeographic model constructed by Darwin; (5) Michael Paul Kinch and (...) the ideas discussed in the 19th century about the geographical distribution of living beings; (6) Janet Browne, who highlighted the importance of the pre-Darwinian naturalists; (7) Peter Bowler, who focused mainly on the influence of paleontology on biogeography; (8) James Larson, who looked into the practices of the naturalists of Northern Europe in the late 18th century; and (9) Malte Ebach, who like Larson, was more interested in analysing the practices rather than the ideas of naturalists who studied the geographical distribution of organisms. Finally, these works are compared with each other. There has not been a dominant paradigm in the construction of historical narratives of biogeography; however, they provide a useful context for understanding problems of biogeography that continue to be debated to this day. (shrink)

Recent discussion of mechanism has suggested new approaches to several issues in the philosophy of science, including theory structure, causal explanation, and reductionism. Here, I apply what I take to be the fruits of the Ônew mechanical philosophyÕ to an analysis of a contemporary debate in evolutionary biology about the role of natural selection in speciation. Traditional accounts of that debate focus on the geographic context of genetic divergence— namely, whether divergence in the absence of geographic isolation is possible (or (...) significant). Those accounts are at best incomplete, I argue, because they ignore the mechanisms producing divergence and miss what is at stake in the biological debate. I argue that the biological debate instead concerns the scope of particular speciation mechanisms which assign different roles to natural selection at various stages of divergence. The upshot is a new interpretation of the crux of that debate—namely, whether divergence with gene flow is possible (or significant) and whether the isolating mechanisms producing it are adaptive. Ó 2005 Elsevier Ltd. All rights reserved. (shrink)

In a series of articles and in a recent book, What Darwin Got Wrong, Jerry Fodor has objected to Darwin’s principle of natural selection on the grounds that it assumes nature has intentions.1 Despite the near universal rejection of Fodor’s argument by biologists and philosophers of biology (myself included),2 I now believe he was almost right. I will show this through a historical examination of a principle that Darwin thought as important as natural selection, his principle of divergence. The principle (...) was designed to explain a phenomenon obvious to any observer of nature, namely, that animals and plants form a hierarchy of clusters. Theodosius Dobzhansky made this the motivating observation of his great synthesizing work, Genetics and the Origin of Species (1937): “the living world is not a single array of individuals in which any two variants are connected by a series of intergrades, but an array of more or less distinctly separate arrays, intermediates between which are absent or at least rare. . . Small.. (shrink)

Several stages can be identified in Darwin's effort to formulate natural selection. The first stage corresponded, roughly speaking, to the period up to 1844. It was characterized by Darwin's attempt to base his model of geographic speciation on an individualistic dynamics, with species understood as reproductively isolated populations. Toward the end of this period, Darwin's ignorance of the laws of variations and heredity led him to adopt varieties and species as the units of variations. This had the extremely important effect (...) of stimulating him to consider the process of speciation as involving populations. At the end of this period, Darwin also began to regard adaptation as being exclusively toward places in the economy of nature. Thus he faced the problem of integrating the process of natural selection with the process of speciation. Individual variants were the units that fueled the first process, whereas varieties produced new speices. There was no link between adaptation and speciation, except whatever could be supplied by a quasi-historical, developmental idea of optimizing the amount of life.In the second stage, I contend, Darwin's reading of Milne-Edwards crystallized his previous insights into a coherent whole. Milne-Edwards' comments on the advantage of functional specialization could readily be understood in terms of the advantage accruing to the individual, relative to other members of its species, from occupying a different niche. Milne-Edwards' discussion of the division of labor suggested that organisms which moved into unoccupied niches would enjoy reduced competition, and hence a differential advantage in survival and reproduction; thus they would induce the species to do likewise. Rather than base his explanation on an analogy with the artificial economy, Darwin chose the principle of the optimalization of the amount of life per unit area as the overall explanatory principle. The difficulties connected with integrating different levels of description were therefore circumvented, insofar as the problem of diversity and speciation was concerned. Although natural selection considered individuals as the units of selection, and the units of variations were varieties and species, the dynamics of the process understood in terms of natural selection, competition, division of labor and niches could give a plausible account of how individual advantage could be transferred to the species, and how diversity resulted from this mechanism. The problem of the different levels of descriptions was confined to how the properties of variations in individuals (in particular, the frequency of variations and their transmission) were responsible for the assumed variability characteristic of varieties and species. This problem Darwin never solved.A third stage occurred in 1858 with the amalgamation of the tree-of-life vizualization of the process of speciation. Speciation, geographic distribution, and systematics were all then embedded in a conceptual matrix with vast explanatory powers. (shrink)

Are species real categories or just conventions? Are species natural kinds? Are teleological statements a distinctive feature of biology? Can life sciences escape from teleology? These are common issues in philosophy of biology. This paper aims to show that in order to answer to each of these questions it is inevitable to take a position respecting the others. Therefore, there is a historical relation between the concept of species and teleological issues. In order to analyse such relation, I will take (...) a historical perspective.After making such historical reconstruction focused on the Aristotle, Linnaeus, Buffon and Lamarck thoughts, I will analyse the Darwinian peculiar view respect teleology and his ideas about species. Although Darwin set out the collapse of teleological essentialisms in biology, there are important vestiges of teleology in his theory. (shrink)

Historians tend to speak of the problem of the origin of species or the species question, as if it were a monolithic problem. In reality, the phrase refers to a, historically, surprisingly fluid and pluriform scientific issue. It has, in the course of the past five centuries, been used in no less than ten different ways or contexts. A clear taxonomy of these separate problems is useful or relevant in two ways. It certainly helps to disentangle confusions that have inevitably (...) emerged in the literature in its absence. It may, secondly, also help us to gain a more thorough understanding, or sharper view, of the history of evolutionary thought. A consequent problem-centric look at that history through the lens of various origin of species problems certainly yields intriguing results, including and particularly for our understanding of the genesis of the Wallace–Darwin theory of evolution through natural selection. (shrink)

Joseph Hooker first learned that Charles Darwin believed in the transmutation of species in 1844. For the next 14 years, Hooker remained a "nonconsenter" to Darwin's views, resolving to keep the question of species origin "subservient to Botany instead of Botany to it, as must be the true relation." Hooker placed particular emphasis on the need for any theory of species origin to support the broad taxonomic delimitation of species, a highly contentious issue. His always provisional support for special creation (...) waned during the 1850s as he lost faith in its expediency for coordinating the study of plant geography, systematics and physiology. In 1858, Hooker embraced Darwin's "considerable revolution in natural history," but only after Darwin had carefully molded his transmutationism to meet Hooker's exacting specifications. (shrink)