The world's foremost geneticist surveys the major developments in what is emerging as the most important single area of scientific inquiry in the twentieth century: biological theory of evolution.

It is often claimed that one of Darwin''s chief accomplishments was to provide biology with a non-teleological explanation of adaptation. A number of Darwin''s closest associates, however, and Darwin himself, did not see it that way. In order to assess whether Darwin''s version of evolutionary theory does or does not employ teleological explanation, two of his botanical studies are examined. The result of this examination is that Darwin sees selection explanations of adaptations as teleological explanations. The confusion in the nineteenth (...) century about Darwin''s attitude to teleology is argued to be a result of Darwin''s teleological explanations not conforming to either of the dominant philosophical justifications of teleology at that time. Darwin''s explanatory practices conform well, however, to recent defenses of the teleological character of selection explanations. (shrink)

How, according to Darwin, does chance variation affect evolutionary outcomes? In his 1866 book, On the Various Contrivances by which British and Foreign Orchids are Fertilised by Insects, Darwin developed an argument that played an important role in his overall case for evolution by natural selection, as articulated in later editions of the Origin. This argument also figured significantly in Darwin's reflections on the theological dimensions of evolution by natural selection.

Darwinian evolutionary biology has often been criticized for appealing to the notion of 'chance' in its explanations. According to some critics, such appeals exhibit the explanatory poverty of evolutionary theory. In response, defenders of Darwinism sometimes downplay the importance of 'chance' in evolution. I believe that both of these approaches are mistaken. The main thesis of this paper is that the term 'chance' encompasses a number of distinct concepts, and that at least some of these concepts serve essential explanatory functions (...) in evolutionary biology. This claim is defended by way of an historical survey of the major concepts of 'chance' in the history of evolutionary biology, especially the concepts used by Jean Baptiste Lamarck, Charles Darwin, and Sewall Wright. An examination of their biologies shows how the concepts of 'chance' used cohere with their major scientific objectives and methods. These concepts survive and continue to function as important explanatory factors in contemporary evolutionary biology. Examples of such usage are given, and the explanatory status of 'chance' assessed. (shrink)

If we arrange in chronological order the various statements Darwin made about God, creation, design, plan, law, and so forth, that I have discussed, there emerges a picture of a consistent development in Darwin's religious views from the orthodoxy of his youth to the agnosticism of his later years. Numerous sources attest that at the beginning of the Beagle voyage Darwin was more or less orthodox in religion and science alike.78 After he became a transmutationist early in 1837, he concluded (...) that the doctrine of secondary causes must be extented even to the history of life and that after the first forms of life were created, there was no further need for divine intervention, except where man was concerned. Man's body, he thought, was produced by the process of transmutation, but he believed for a time that man's soul was “superadded.” By mid-1838 he had become convinced that nothing, after the creation of life, was due to miracles. God works only through laws, which are capable of producing “every effect of evey kind which surrounds us.” The existence of man, the idea of God in man's mind, and the harmony of the whole system were in his eyes prearranged goals of deterministic laws imposed by God. Such a conception excludes the miracles on which Christianity depends; but it is not possible to say whether Darwin's loss of Christian faith, which occurred at about this same time, preceded and made possible his “materialism” or was rather caused or hastened by it.79 In the weeks after his reading of Malthus, Darwin's belief in a plan of creation gave way to the belief that God created matter and life and designed their laws, leaving the details, however, to the workings of chance. This remained his view until the 1860s.There is no exact parallel between this development of Darwin's religious views and the development of his ideas on evolution, but there is a general correspondence. When he believed in a plan of creation, Darwin's theory of transmutation did not depend on struggle or the selection of chance variations. Adaptation was, for him, an automatic response to environmental chance. From late 1838 to 1859 he believed in designed laws and chance, and this belief, too, has its parallel in his theory. The element of chance in natural selection meant that there could be no detailed plan,in which even man's idea of God would be a necessary outcome of nature's laws (man himself is not a necessary outcome of the working of natural selection).80 But Darwin still believed nature was programmed to achieve certain general ends. We might say that he believed in a general, though not a special, teleology. Natural selection was for him a law to maximize utility, creating useful organs, retaining vestiges for future use. For many years it was a law designed to produce organisms perfectly adapted to their environments. Only later did Darwin come to doubt even this sort of design in nature.81 One way of describing the development of Darwin's evolutionary thought is to say that it shows a gradual abandoning of his “theistic” assumptions, so that by the late 1860s his theory was informed to a slighter extent by notions of purpose and design than it was in 1838 or 1844 or 1859. (shrink)

Charles Babbage was an English mathematician, philosopher and mechanical engineer who invented the concept of a programmable computer. From 1828 to 1839 he was Lucasian Professor of Mathematics at Cambridge, a position whose holders have included Isaac Newton and Stephen Hawking. A proponent of natural religion, he published The Ninth Bridgewater Treatise in 1837 as his personal response to The Bridgewater Treatises, a series of books on theology and science that had recently appeared. Disputing the claim that science disfavours religion, (...) Babbage wrote 'that there exists no such fatal collision between the words of Scripture and the facts of nature'. He argues on the basis of reason and experience alone, drawing a parallel between his work on the calculating engine and God as the divine programmer of the universe. Eloquently written, and underpinned by mathematical arguments, The Ninth Bridgewater Treatise is a landmark work of natural theology. (shrink)

Darwin''s biology was teleological only if the term teleology is defined in a manner that fails to recognize his contribution to the metaphysics and epistemology of modern science. His use of teleological metaphors in a strictly teleonomic context is irrelevant to the meaning of his discourse. The myth of Darwin''s alleged teleology is partly due to misinterpretations of discussions about whether morphology should be a purely formal science. Merely rejecting such notions as special creation and vitalism does not prevent the (...) pernicious effects of teleological reasoning, even at the present time. (shrink)