This work takes a stand on whether Wallace should be regarded as co-author of the theory of natural selection alongside Darwin as he is usually considered on behalf of his alleged essential contribution to the conception of the theory. It does so from a perspective unexplored thus far: we will argue for Darwin’s priority based on a rational reconstruction of the theory of natural selection as it appears in the writings of both authors. We show that the theory does not (...) appear in exactly the same manner in the writings of each of its alleged co-discoverers: tough we find the same fundamental elements in both works, even in Darwin’s early texts, we discern a more complex unifying and ramified structure than the one we find in Wallace’s Ternate manuscript. Even when we think the badge of the “Darwin–Wallace” theory is well deserved, the unifying force of Darwin’s version has proved to be one of the keys for the ulterior success of the so-called Darwinian revolution in Biology. (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)

Wallace's contributions to biological thought tend to be overlooked or overly praised, neither of which produces a satisfactory assessment. Examples of the latter tendency are the recent expositions by Brackman and Brooks; although both books contain much worthwhile material, both are flawed. At critical points their theories fail to measure up, Brackman's because of his misinterpretations of events in the month of June 1858, and Brooks's Darwin's September 5 letter to Gray could, and probably did, represent an ordering of his (...) ideas in response to a felt challenge.A fruitful way to characterize the relationship between Darwin and Wallace may be found in terms of game theory. Most scholars look upon the relationship as a zero-sum game, with a winner and a loser, the matter of priority being considered as a “single event.” Another approach would be to look upon it as a non-zero-sum game with each man influencing the other. In this case, the productivity of one is stimulated by the contributions of the other, resulting in a net gain in knowledge overall, and both men become winners, or codiscoverers. This approach is possible if Wallace's contributions to the theory of evolution by means of natural selection are recognized. (shrink)

For over a century it has been believed that Alfred Russel Wallace and Henry Walter Bates set out for the Amazon in 1848 with the aim of “solving the problem of the origin of species”. Yet this enticing story is based on only one sentence. Bates claimed in the preface to his 1863 book that Wallace stated this was the aim of their expedition in an 1847 letter. Bates gave a quotation from the letter. But Wallace himself never endorsed or (...) repeated this story. Many writers have acknowledged that this letter still survives. Yet the wording is different from that quoted by Bates and the letter says nothing of an expedition. It is argued that the sentence given by Bates is not a genuine quotation from this or any other Wallace letter but was modified by Bates to promote his own reputation. More significantly, this leads to the conclusion that there was a very sudden and dramatic shift in the way species were thought of and discussed after Darwin’s Origin of species appeared. Something called “the problem of the origin of species” never occurred before Darwin’s book but exploded in frequency immediately after it. A profound change in how species origins were discussed happened which no one seemed to notice. (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)