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)

1990 marked the 150th anniversary of the publication of Charles Darwin's first major scientific theory. The paper, first presented by Darwin to the Geological Society of London on 7 March 1838, was entitled ‘On the Connexion of Certain Volcanic Phenomena and on the Formation of Mountain-Chains and the Effects of Continental Elevations.’ The paper was a remarkable attempt to develop a global tectonic synthesis. It was the culmination of a period of intensive geological activity by Darwin – then twenty-nine – (...) who had returned from the Beagle voyage only eighteen months previously. The present article reviews the development of Darwin's views, their impact upon his contemporaries, their role in shaping his later views on the origin of species, and their significance in scientific theory-making. It draws, in part, on Darwin's unpublished geological notes and jottings. This paper, and the papers by Sandra Herbert and James Secord that accompany it, were delivered at a symposium which I organized at the Geological Society of London on 31 October 1988 to mark the 150th anniversary of the reading of Darwin's paper. (shrink)

History is the science which investigates the successive changes that have taken place in the material and intellectual conditions of man; it inquires into the causes of those changes, and the influence which they have exerted in modifying the life and mind of mankind.

Early in June of 1867, Charles Darwin turned back the cover of his copy of the respected quarterlyNorth British Review, to find on its opening pages a lengthy essay attacking his theory of natural selection. As with the vast majority of articles in the Victorian periodicals, the review was anonymous, prompting immediate speculation in Darwin's circle as to the author's identity. It was to be about a year-and-a-half before Darwin would learn that the engineer Fleeming Jenkin had written the essay. (...) By then, Darwin had concluded that the critique was the most valuable he had ever read onThe Origin of Species. (shrink)

This paper aims to establish the connection between the theoretical and practical aims of the Office of the Hydrographer of the British Admiralty and Charles Darwin’s (1809–1882) work on coral reefs from 1835 to 1842. I also emphasize the consistent zoological as well as geological reasoning contained in these texts. The Office’s influences have been previously overlooked, despite the Admiralty’s interest in using coral reefs as natural instruments. I elaborate on this by introducing the work of Alexander Dalrymple (1737–1808), the (...) first hydrographer of the Admiralty and a figure who has flown under the radar of the history of coral reef theories. I show that Dalrymple introduced a unified account of coral reefs in which multiple features of the coral reefs, such as their shape, slope of the sides, ridges, channels, and elevation relative to the water, were all explained by the action of the winds and waves—and proposed that one could use these features to predict seafaring conditions around the islands. Then, I show that Darwin’s “Coral Islands” (1835) and his _Coral Reefs_ monograph (1842) spoke to these hydrographical issues and did so, at times, by way of zoological reasoning. It was, for instance, the coral behavior and the related notion of a zoological or botanical _station_ that ultimately proved the biggest blow to the Admiralty’s aim to use the coral reefs as instruments because it eroded many uniform predictions regarding the past or future of a coral reef. Connecting these themes leads us to a surprising conclusion: that Darwin’s theory of coral reefs, long a model instance of Darwin making uniform predictable inferences, was, in actuality, also his first formal encounter with something at times the entire opposite. (shrink)

On occasion Charles Darwin can seem our scientific contemporary, for the subjects he engaged remain engaging today, but in his role as author he belongs to the past. It is not customary today for scientists to write book after book, as Darwin did, or for these books to serve as the primary vehicle of scientific communication. For Darwin, however, the book was central. He wrote at least eighteen, depending on what one counts; in hisAutobiographyhe entitled the section describing his most (...) important work ‘An account how several books arose’; and in his personal Journal, begun in August 1838 after he had come to a mature sense of himself, he organized entries around his books. A characteristic entry is that for 1846: ‘Oct. 1st. Finished last proof of my Geolog. Observ. on S. America; This volume, including Paper in Geolog. Journal on the Falkland Islands took me 18 & 1/2 months:–’. Further, almost always he had a book under way: when one was complete, the next was begun. He called them the milestones to his life. (shrink)

INTRODUCTORY REMARKS It is my lot, if not my duty, in presenting these opening remarks at our conference, to take the title of our meeting seriously. ...

The development of geology during the first half of the nineteenth century is now considered to be more complicated than was once thought. The positivistic picture of two conflicting schools, one of them allegedly modern and progressive, the other supposedly conservative and scriptural, is too simplistic and misleading. First, the influence of the Bible has been exaggerated. It is true that in the seventeenth and eighteenth centuries the Flood had been given an important role as a geological agent, but in (...) the early nineteenth century there were hardly any professional geologists who defended this view. At least, it is not correct to associate either neptunism, catastrophism, or diluvialism with the Mosaic tradition. Secondly, the use of such terms as ‘catastrophism’ and ‘diluvialism’ has been unfortunate in so far as they have led to biblical associations; these terms must be given a more precise meaning. Thirdly, in the evaluation of the geology of the period, not enough weight has been given to the historical context. From our knowledge of modern geology alone it is not possible to judge what was loose speculation or empirical science at that time. Lyell's contributions to geology, as well as those of his opponents, should be considered and examined in more detail. (shrink)

The theoretical system Lyell presented in 1830 was composed of three requirements or principles: 1) the Uniformity Principle which states that past geological events must be explained by the same causes now in operation; 2) the Uniformity of Rate Principle which states that geological laws operate with the same force as at present; 3) the Steady-state Principle which states that the earth does not undergo any directional change. The three principles form a single thesis called uniformitarianism which has been repeatedly (...) questioned and which has been reputed to be unable to face the competing directional synthesis based on the theory of the earth's cooling down. As a result, the significance of Lyell's system has been reduced to a simple actualism which admits the validity of the only Uniformity Principle. I believe that the only way to understand Lyell's role in the history of science is to maintain the unity of his synthesis. To show the Newtonian roots of this synthesis I will compare Lyell's principles and Newton's Rules of Reasoning. I will conclude with an analysis of the methodological function of principles in Lyell's scientific endeavour. (shrink)