Summary The common view has been that Darwin regarded species as artificial and arbitrary constructions of taxonomists, not as distinct natural units. However, in his transmutation notebooks he clearly subscribed to the reality of species, on the basis of the criterion of non-interbreeding. A consequence of this biological species concept was his identification of the acquisition of reproductive isolation as the mark of the completion of speciation. He developed in the notebooks a theory of geographic speciation on the grounds of (...) (a) an empirical correlation between barriers and the geographical distributions of allied species, (b) the analogy of artificial isolation in the formation of new domesticated varieties, and (c) the logical consequence of blending inheritance. A brief discussion of Darwin's species concept in later writings concludes the paper. (shrink)

The Nature of Selection is a straightforward, self-contained introduction to philosophical and biological problems in evolutionary theory. It presents a powerful analysis of the evolutionary concepts of natural selection, fitness, and adaptation and clarifies controversial issues concerning altruism, group selection, and the idea that organisms are survival machines built for the good of the genes that inhabit them. "Sober's is the answering philosophical voice, the voice of a first-rate philosopher and a knowledgeable student of contemporary evolutionary theory. His book merits (...) broad attention among both communities. It should also inspire others to continue the conversation."-Philip Kitcher, Nature "Elliott Sober has made extraordinarily important contributions to our understanding of biological problems in evolutionary biology and causality. The Nature of Selection is a major contribution to understanding epistemological problems in evolutionary theory. I predict that it will have a long lasting place in the literature."-Richard C. Lewontin. (shrink)

Explores the development of the ideas of evolutionary biology, particularly as affected by the increasing understanding of genetics and of the chemical basis of inheritance.

One of science's greatest intellects examines how people and animals display fear, anger, and pleasure. Darwin based this 1872 study on his personal observations, which anticipated later findings in neuroscience. Abounding in anecdotes and literary quotations, the book is illustrated with 21 figures and seven photographic plates. Its direct approach, accessible to professionals and amateurs alike, continues to inspire and inform modern research in psychology.

The publication of Darwin's On the Origin of Species in 1859 ignited a public storm he neither wanted nor enjoyed. Having offered his book as a contribution to science, Darwin discovered to his dismay that it was received as an affront by many scientists and as a sacrilege by clergy and Christian citizens. To answer the criticism that his theory was a theory only, and a wild one at that, he published two volumes in 1868 to demonstrate that evolution was (...) obvious to anyone who cared to look at a bull in a pasture or a dog on a hearth. In response to those who insisted that species were distinct since creation, Darwin pointed to breeders of pigs and pigeons. In reply to those who protested that human intervention is one thing and natural selection another, he argued, "If organic beings had not possessed an inherent tendency to vary, man could have done nothing." To counter those who scorned his descriptions of species in exotic places, he submitted local evidence of cabbages and cauliflower. Based on a wide array of sources, from ancient pictographs to Polish roosters, from skins and from skeletons, from scientific journals and breeding manuals, Darwin assembled a mass of proof--and a hypothesis about species reversion that risked his reputation anew. The Variation of Animals and Plants under Domestication is a two-volume compilation of his thorough and intensive research and the revolutionary conclusions that resulted. The first portion of his work is dedicated to a meticulous analysis of various aspects of plant and animal life, including an inventory of varieties and their physical and behavioral characteristics, investigation of the impact of a species' surrounding environment and the role that both natural and forced changes in this environment have had. Darwin then turns to a richly detailed discussion of the roles of inheritance and crossing in the development of species. A wealth of illustrations further support and enhance his findings. This fascinating, invaluable, and courageous undertaking eventually formed the foundation for our current understanding of evolution. "In science as in politics the victors tend to write the history books. As a result, the record of the past is edited, intentionally or unintentionally, so that it focuses mainly on the precursors of contemporary orthodoxy. Such a focus may accurately represent the genealogy of modern ideas, but it almost inevitably misrepresents the historical experience of their progenitors... Even the powerful, persuasive, and ultimately triumphant theory of evolution by natural selection required not only defense, but repeated buttressing and revision. Variation showed Darwin hard at work on this rearguard action, using the materials he had at hand... His information was gleaned from the observations of fanciers, breeders, and amateur naturalists, as well as from the treatises of those on the cutting edge of zoology and botany. As hindsight narrows the historical spotlight, it imposes its own sense of hierarchy on the preoccupations of the past. But Darwin was interested in all of these topics, valued all of these sources, and belonged, to a greater or lesser extent, to all of these communities."--from the Introduction. (shrink)

This article is primarily a study of the group selection controversy, with special emphasis on the period from 1962 to the present, and the rise of inclusive fitness theory. Interest is focused on the relations between individual fitness theory and other fitness theories and on the methodological imperatives used in the controversy over the status of these theories. An appendix formalizes the notion of "assertive part" which is used in the informal discussion of the methodological imperatives elicited from the controversy.

What is the Darwinian revolution and why is it important for philosophers? These are the questions tackled in this Element. In four sections, the topics covered are the story of the revolution, the question of whether it really was a revolution, the nature of the revolution, and the implications for philosophy, both epistemology and ethics.

Darwin only published one account of his provisional hypothesis of pangenesis, and that is to be found in chapter xxvii of his bookThe Variation of Animals and Plants under Domestication, the first edition of which is dated 1868. The absence of any earlier account in Darwin's works has led some to assume that he had recourse to this hypothesis only a short time before the published date of the book containing it, and on the basis of this assumption they have (...) asserted that he produced it as a part of his defence of the theory of evolution against the criticisms made of it by the physicists Sir William Thomson, afterwards Lord Kelvin, and Fleeming Jenkin. But to make such an assertion is to ignore the fact that Darwin had already sent his manuscript of pangenesis to Huxley in the year 1865, two years before Fleeming Jenkin's article appeared and three years before Lord Kelvin openly attacked the evolutionary theory. The discovery of this manuscript of pangenesis has, therefore, some importance, for it should reveal Darwin's conception of pangenesis in 1865. (shrink)

The central role played by Darwin's analogy between selection under domestication and that under nature has been adequately appreciated, but I have indicated how important the domesticated organisms also were to other elements of Darwin's theory of evolution-his recognition of “the constant principle of change,” for instance, of the imperfection of adaptation, and of the extent of variation in nature. The further development of his theory and its presentation to the public likewise hinged on frequent reference to domesticates.We have seen (...) that Darwin's reliance on the analogy between domesticated varieties and wild species was a bold and original step, in light of contemporary views on the nature of domesticates. However, as Darwin undoubtedly foresaw, his reliance on the analogy created difficulties as well as solving problems, and these began with his Malthusian codiscoverer of the principle of natural selection, Alfred Russel Wallace. Wallace's paper “On the Tendency of Varieties to Depart Indefinitely from the Original Type,” presented to the Linnean Scoiety along with the first public unveiling of Darwin's theory, states: We see, then, that no inferences as to varieties in a state of nature can be deduced from the observation of those occurring among domestic animals. The two are so much opposed to each other in every circumstance of their existence, that what applies to the one is almost sure not to apply to the other. Domestic animals are abnormal, irregular, artificial; they are subject to varieties which never occur and never can occur in a state of nature.62Much has been made of the similarity of views of Darwin and Wallace, but this quotation surely reveals how utterly different their views were on what to Darwin was an important matter. Several critics of the Origin saw Darwin's reliance on the domesticates as his Achilles heel. As Young has pointed out, Samuel Wilberforce included the following passage in his attack on the Origin: Nor must we pass over unnoticed the transference of the argument from the domesticated to the untamed animals. Assuming that man as the selector can do much in a limited time, Mr. Darwin argues that Nature, a more powerful, a more continuous power, working over vastly extended ranges of time, can do more. But why should Nature, so uniform and persistent in all her operations, tend in this instance to change? Why should she become a selector of varieties?63Another critic, Fleeming Jenkin, found the analogy a weakness in Darwin's theory because of the limited extent of variation in any one direction in domestic animals and plants.64 We have already seen that Darwin had confided a similar view to his notebook thirty years earlier, but changed his mind as a result of his profound study of domesticates. De Beer's reference to “an English country gentleman's knowledge of domestic plants and animals and their breeding”65 fails totally to recognize the originality and depth of Darwin's knowledge of domesticates.Why did Darwin, against the currents of his time, rely so heavily on mankind's experience with domesticated organisms to shape his theory about species in nature? On reason is that only with domesticates was an approach that came close to experimental verification possible. Darwin fully realized the inadequacies of the experiment, as is emphasized by his repeated contrasting of selection under nature and selection by man. Yet the extensive experience and data of plant and animal breeders offered the only reliable base against which Darwin could continually challenge his views. As he wrote in the introduction to Variation, with domestication, “man ... may be said to have been trying an experiment on a gigantic scale.”66 Given Darwin's high opinion of the quantitative work of Malthus and Quetelet (as emphasized by Schweber),67 and his unremitting efforts to secure data by which to test his theories, it was inevitable that he should attach high significance to domesticated varieties. John Tyndall, in his Belfast address of 1874, said: “The strength of the doctrine of Evolution consists, not in experimental demonstration (for the subject is hardly accessible to this mode of proof), but in its general harmony with scientific thought.”68 Darwin would have agreed with the latter thought, but I think he would have challenged the preceding one on the grounds that long experience with domesticated varieties did provide an element of experimental demonstration. It gave him confidence in his theory, and he used his vast knowledge of artificial selection boldly and creatively. (shrink)

“The difficulty of discussion between people brought up in different frameworks is to be admitted,” Karl Popper writes. “But nothing is more fruitful than such a discussion; than the culture clash which has stimulated some of the greatest intellectual revolutions.”71 Certainly Kirby and Darwin were brought up in different cultures — Kirby with his Anglican-Tory orientation, Darwin with his Whig-liberal background — and certainly the clash generated some interesting theories; but it also resulted in the revival of Lamarck's discredited habit (...) theory, which took another century of careful experimentation to weed out. (shrink)

A coherent treatment of the flow of ideas throughout Darwin's works, this volume presents a unified theoretical system that explains Darwin's investigations, evaluating the literature from a historical, scientific, and philosophical perspective.

The question of the levels at which natural selection can be said to operate is much discussed by biologists today and is a key factor in the recent controversy about sociobiology. It is shown that this problem is one to which Charles Darwin addressed himself at some length. It is argued that apart from some slight equivocation over man, Darwin opted firmly for hypotheses supposing selection always to work at the level of the individual rather than the group. However, natural (...) selection's co-discoverer, Alfred Russel Wallace, endorsed group selection hypotheses. (shrink)

Darwin discusses why different muscles are brought into action under different emotions and how particular animals have adapted for association with man.