Chapter Six Darwinism, Disvalues and Design Section 1: Darwinism It is time to say more about Darwinism, partly to explain its coherence and cogency, partly to introduce its implications for the Teleological Argument, and partly to illustrate and appraise the problem of natural evil which, as we have seen, contributed to Darwin’s own loss of belief in God. Darwinism will be discussed in the current section, together with some of its grounds and some of its varieties, to which we revert in later chapters. Its possible implications in the area of sociobiology will also be considered. In later sections of this chapter its bearing will be considered on the Design Argument, as will subsequently its compatibility with belief in God’s goodness. The theory of evolution by natural selection provides the backdrop for contemporary environmental concern, and several of the themes of this chapter will thus prove relevant to the scope and limits of environmental stewardship, discussed in the final two chapters of this book. Darwin’s theory asserts, in part, that life on Earth has evolved from a common ancestry1 and from relatively simple to relatively complex forms of life.2 Michael Ruse summarizes Darwin’s evidence as including grounds from palaeontology (the fossil record), bio-geography (for evolution best explains the distribution of bird and reptile species in places such as the Galapagos Islands), anatomical similarities across diverse species (for evolution from common ancestors best explains such ‘homologies’), and from systematics, for common ancestry best explains the way species can be ordered in a hierarchy of groups, which seem to call for an explanation of such a nature.3 In view of this and additional evidence (like that from embryology), the evolution of species was soon recognized as a fact.4 Darwin further argued that a major cause of the adaptedness of organisms that facilitates their evolution was natural selection. Because more individual organisms are produced than can survive, there is competition for survival, and only the fittest survive and reproduce. Darwin was hereby generalizing the findings of Thomas Robert Malthus to all biological populations, and deducing relevant Taylor & Francis. Not for Distribution implications. His central grounds, however, were an argument by analogy with 1 Michael Ruse (2001), Can a Darwinian Be a Christian?, pp. 12–18. 2 Alvin Plantinga (1991), ‘When Faith and Reason Clash: Evolution and the Bible’, p. 684. 3 Ruse, op. cit., pp. 13–18. 4 Ruse, ibid., pp. 20 and 25. 110 Creation and Evolution the artificial selection among animal and plant varieties conducted by human breeders who select and breed from the best available variants;5 thus Darwin’s analogical argument was to supersede the previously influential analogical argument of William Paley who had explained adaptations by a cosmic watch- maker or designer. More recently, Richard Dawkins has developed this analogical argument as supporting apparent design by a ‘blind watch-maker’, or in other words natural selection, adding to this conclusion a rejection of any other designer;6 the suggestion (detected by some in the text of Darwin7) that natural selection may be regarded as personal and intentional is firmly excluded. The source of the variations on which natural selection operates was unknown to Darwin, who also adhered to mistaken beliefs about heredity; but when the work of his contemporary, Gregor Mendel, on genetics and on random mutations, was rediscovered at the turn of the century and developed by researchers such as Ronald Fisher in the 1930s, it became possible to explain both the origination of beneficial characteristics and their survival down the generations, and thus establish a broad Darwinian consensus among most scientists.8 However, critics of Darwinism sometimes complain that natural selection explains nothing, since the survival of the fittest simply means the survival of those fittest to survive, and this principle is an empty, unfalsifiable tautology. Yet, as Gallagher has replied, the theory of evolution (as opposed to this principle) supplies an informative explanation both of variations, of some traits being more advantageous than others, of selection between them, and of the related development of populations and species. Thus while Darwinists from Ruse to Stephen Jay Gould have tried but failed to make the actual principle into a substantive claim, the theory remains a substantive one. If this were not so, it could not be contested by its creationist and other opponents as misguided.9 So the theory of natural selection cannot be written off as lacking any scientific role. Meanwhile the principle effectively tells us to seek explanations of biological survival in the area of an organism’s adaptation to its natural environment; this is a methodological directive, rather than a statement, but one grounded in the theory of natural selection,10 and thus not lightly to be sneezed at. Darwin and his mainstream successors have taken the view that the variations that are important for natural selection are invariably small ones, despite the availability of larger variations, or ‘hopeful monsters’ as he called them; evolution Taylor & Francis. Not for Distribution 5 Ruse, ibid., pp. 22–3. 6 Richard Dawkins (1986), The Blind Watchmaker. 7 Gillian Beer (1983), Darwin’s Plots, pp. 68–71. 8 Ruse, op. cit., pp. 25–6. 9 Kenneth T. Gallagher (1989), ‘“Natural Selection”: A Tautology?,’ International Philosophical Quarterly, 29, 17–31. Gallagher’s stance was substantially anticipated at Karl Popper (1972), Objective Knowledge: An Evolutionary Approach, pp. 69–70. 10 Gallagher, op. cit., pp. 29–30. Darwinism, Disvalues and Design 111 is a gradual process, without jumps or ‘saltations’.11 Some of his supporters, however, including Thomas Henry Huxley, have regarded saltations as better explaining e.g. the evolution of the eye;12 indeed saltationism remains a minority position among some Darwinians (including distinguished ones such as John Maynard Smith).13 But most regard gradualism as essential to the theory of natural selection, holding that on no other basis can the evolution of biological complexity and adaptedness be explained.14 To this claim we shall be returning (see Chapter Seven, Section 4 below). Gradualism is consistent with the theory of Gould and Niles Eldredge (whatever these authors may have held to the contrary) that evolution consists of long periods of imperceptible change punctuated by episodes where change is rapid (punctuated equilibria), since rapid change could still be due to a rapid sequence of small variations.15 Darwinians also diverge over whether natural selection is the sole cause (or the sole important cause) of most biological phenomena (adaptationism),16 or whether there are other factors at work. Darwin himself firmly expressed the latter view, in the last edition of Origin of Species.17 The view that there are other important factors has been defended by Gould and Richard C. Lewontin. They Distribution argue that just as spandrels (triangular tapering concave surfaces formed by the intersection of two rounded arches at right angles) such as those of St. Mark’s Cathedral at Venice bear designs that make them seem central to the architect’s for purpose, but are in fact inevitable by-products of any building plan involving a dome and arches, so biological phenomena can be by-products of factors other than selection, such as inherited ‘building plans’ that were adaptive for earlier Not stages in life or for earlier generations or for ancestral species (such as homologies in bone structures between birds and mammals).18 Further possibilities are listed; most striking is that of the secondary utilization of parts present for other reasons. (Thus even if blushing is an adaptation for sexual selection in humans, it cannot figure in explanations of why blood is red.19) In a later paper, Gould and Elisabeth 11 Francis. Ruse, op. cit., p. 23. 12 Ruse, ibid., p. 25. & 13 John Maynard Smith (1981), ‘Did Darwin Get it Right?’, London Review of Books, 3.11, 10–11; see also Maynard Smith (1982), Evolution and the Theory of Games; and Ruse, op. cit., p. 30. 14 Ruse, ibid., p. 136; thus Dawkins, The Blind Watchmaker. 15 Niles Eldredge and Stephen Jay Gould (1972), ‘Punctuated Equilibria: An Alternative to Phyletic Gradualism’, in T.J.M. Schopf, (ed.), Models in Paleobiology, Taylor 82–115. 16 Elliott Sober (1998), ‘Six Sayings about Adaptationism’, in David L. Hull and Michael Ruse, The Philosophy of Biology, 72–86, p. 72. 17 Darwin (1872), The Origin of Species (Darwin’s last edition), p. 395. 18 Stephen Jay Gould and Richard C. Lewontin (1994), ‘The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme’, in Elliott Sober (ed.), Conceptual Issues in Evolutionary Biology (2nd edn), 73–90. 19 Gould and Lewontin, ibid., p. 85. 112 Creation and Evolution S. Vrba coin the term ‘exaptations’ for features that are fit for their current role but not ‘designed’ and/or selected for it, such as lactation in mammals (granted that lactose-like chemicals probably evolved not for nourishing the young but to kill bacteria) or the supportive role of bones, originally selected as stores for phosphates rather than for rigidity.20 Nevertheless, as Ruse affirms, Gould and his fellow-writers remain Darwinists, recognizing both evolution from a common ancestry, and natural selection as the most important source of biological adaptation and evolution. Gould has himself recently expounded and defended this generic Darwinism,21 which can be combined with a rejection of the kind of sociobiological explanations of human behaviour adopted by Dawkins.22 Yet other Darwinians combine recognition of natural selection with the view that there is much in the realm of biology that lies beyond its scope, such as change at the molecular level, as studied by Motoo Kimura.23 Adaptationists reply to their various critics that the very case of anti-adaptationists turns crucially on secondary adaptation and its preconditions, and can thus be reconciled with the centrality of adaptation.24 Ruse calls this position ‘ultra-Darwinism’,25 because it is more Darwinian than Darwin himself was.