Ideas

by Peter Watson

  The term ‘evolution’ was originally used in biology exclusively for the growth of the embryo. In the original Latin it means ‘to unfold’. Outside that usage, terms like ‘progressionism’ or development were used to convey the cohering notion that simpler organisms had, in an as yet unknown fashion, given rise to more complex ones. Experts were divided as to whether this progression included man. Evolution was next used in a cultural sense, following the observations of Vico, Herder and others, who saw in the development of human societies a progression from more primitive to more advanced forms of civilisation. Peter Bowler makes the point that early anthropologists such as E. B. Tylor and L. H. Morgan argued that different races progress through a similar sequence of cultural phases, with peoples who are still ‘primitive’ belonging to ‘retarded lines of cultural development, held up at a stage through which the white race had passed at an earlier phase’.61

  Lamarck was one of the most important advocates of progressionism. Jean-Baptiste de Monet, chevalier de Lamarck (1744–1829), was not quite the knave and fool he has sometimes been painted. It was he who noticed that some fossil species were analogous to creatures that are still living, which gave him the idea that some fossil lines, at least, might not be extinct, but instead had changed, responding to alterations in conditions on earth, and were therefore still living ‘but in an amended form that we don’t recognise’. This is a pre-Darwinian concept of adaptation.62 Lamarck was convinced of the great age of the earth and that life forms had continuously changed over long periods of time. And he considered man the end-product of this progression.63 Lamarck’s idea of evolution was two-fold. In the first place, he believed that nature embodied a principle towards increasing complexity. Second, he believed that organs within any creature developed more strongly the more often they were used and that these strengthened–or acquired–characteristics were passed on to later generations, always ‘provided that the changes acquired are common to both sexes, or to those which produce the young’.64

  Because of these factors, and others, which we shall come to, it has been said that there was something ‘in the air’ in the middle of the nineteenth century, which helped give rise to what Darwin would call natural selection.65 A struggle for existence had been implied by Malthus, as long ago as 1797. Each tribe in history would have competed for resources, he said, with the less successful becoming extinct. ‘It is now known that in addition to Malthus, Darwin gained insights from reading the work of Adam Smith and other political economists. The concept of divergence through specialisation reflects the economic advantages supposed to accrue from the division of labour.’66 Another theory was advanced by William Charles Wells in 1813, ‘An Account of a Female of the White Race of Mankind’, where he suggested that the human races might have been formed when groups moved into unoccupied territory and where they were faced with a new environment.67 Accidental variations within the population would mean that some individuals would be better adapted to the new conditions, who would thus tend to become the parents of the new race.

  Wherever one looked in the mid-nineteenth century, then, the role played by struggle, by competition, in society and in nature, was on everyone’s lips.68 It was by now difficult to contradict the evidence of the rocks, where the basic picture was clear. ‘The earliest rocks [600 million years ago] yielded only the remains of invertebrates, with the first fish appearing only in the Silurian [440–410 million years ago]. The Mesozoic [250–65 million years ago] was dominated by the reptiles, including the dinosaurs. Although present in small numbers in the Mesozoic, the mammals only became dominant in the Cenozoic [65 million years ago the present], gradually progressing to the more advanced creatures of today, including the human species.’69 (The dates in square brackets were not, of course, accepted in the nineteenth century.) It was hard for people not to read some sort of ‘end’ in this progression, ‘leading’, via stages, to humans, ‘and thus revealing a divine plan with a symbolic purpose’. In books of the time, most ‘trees of life’ showed a main stem, thicker than others, leading directly to man.

  This picture, of course, now has to be revised in the light of James Secord’s recent work. In his book, he provides an illustration of Darwin’s notes, made when he was reading Vestiges in the British Museum Reading Room. Darwin was far from impressed by many aspects of the argument (he never bought his own copy of the book), but Vestiges, coming on top of the ‘something in the air’, clearly had an effect in allowing Darwin to sharpen the distinction between his own theory of natural selection and its competitors.70

  A final element in this ‘climate of opinion’, this ‘something in the air’, as regards ‘progressionism’ and how it was achieved, was the work of Alfred Russel Wallace. Wallace’s reputation, and role, in the discovery of evolution have gone through their own progression in recent times. For many years it was accepted that the paper he sent to Darwin in 1858, ‘On the Tendencies of Varieties to Depart Indefinitely from the Original Type’, contained a clear exposition of natural selection, such that Darwin was forced to begin a move towards publication of his own book, On the Origin of Species. As a result, some scholars have argued that Wallace was never given the recognition he deserves and have even implied that Darwin and his followers deliberately kept him out of the limelight.71 More recently, however, a closer reading of Wallace’s paper has shown that his idea about natural selection was not the same as Darwin’s, and that it was much less powerful as an explanatory device. In particular, Wallace did not stress competition between individuals, but between individuals and the environment. For Wallace, the less fit individuals, those less well-adapted to their environment, will be eliminated, especially when there are major changes in that environment. Under this system, each individual struggles against the environment and the fate of any one individual is independent of others.72 This difference, which is fundamental, may explain why Wallace appears to have shown no resentment when Darwin’s book was published the year after he had sent him his paper.73

  None of the foregoing, however, should be allowed to cloud the fact that when On the Origin of Species did appear, in 1859, it introduced ‘an entirely new and–to Darwin’s contemporaries–an entirely unexpected approach to the question of biological evolution’. Darwin’s theory explained, as no one else had done, a new mechanism of change in the biological world. It showed how one species gave rise to another and, in Ernst Mayr’s words, ‘represented not merely the replacement of one scientific theory (“immutable species”) by a new one, but demanded a complete rethinking of man’s concept of the world and of himself; more specifically, it demanded the rejection of some of the most widely held and most cherished beliefs of western man.’ For Peter Bowler, ‘The historian of ideas sees the revolution in biology as symptomatic of a deeper change in the values of western society, as the Christian view of man and nature was replaced by a materialistic one.’74 The most notable flash of insight by Darwin was his theory of natural selection, the backbone of the book (its full title was On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life). Individuals of any species show variations and those better suited were more likely to reproduce and give rise to a new generation. In this way, accidental variations that fitted better than others were encouraged. No ‘design’ was necessary in this theory, or process, which was at the same time far more parsimonious than any other, and could be observed on all sides.75

  Although Darwin had been stimulated to published the Origin after being contacted by Wallace, he had been germinating his ideas since the late 1830s, after his now-famous voyage on the Beagle. His time in South America, in particular the Galapagos Islands, had taught him to think in terms of populations rather than individuals, as he studied variation from island to island. He had become familiar with the common rhea, a flightless bird, while travelling the open pampas of Patagonia, and had eaten different forms of the creature as he moved around. He noticed that, at the edges of the terr
itory occupied by the two populations, there was a struggle for supremacy. And he began to wonder why there were related species on different islands and continents–would the Creator have visited each location and made these fine adjustments?76 From a study of barnacles he noted how much variety was possible in a species, and all these observations and inferences gradually came together. When the book was published, on 24 November 1859, 1,250 copies were snapped up on the first day. He himself took the waters at Ilkley, in Yorkshire, waiting for the storm to break.77 It did not take long and it is not hard to see why: Ernst Mayr concluded that there were six major philosophical implications of Darwin’s theories: (1) the replacement of a static by an evolving world; (2) the demonstration of the implausibility of creationism; (3) the refutation of cosmic teleology (the idea that there was a purpose in the universe); (4) the abolition of any justification for absolute anthropocentrism (that the purpose of the world is the production of man); (5) the explanation of ‘design’ in the world by purely materialistic processes; (6) the replacement of essentialism by population thinking.

  We must be clear about the impact of the Origin. It owed something to Darwin’s solid reputation and because his book was packed with supporting details–it was not produced by a nobody.78 Yet its impact also had something to do with the fact that, as James Secord has pointed out, the book resolved–or appeared to resolve–a crisis, not because it sparked one. Natural selection was, essentially, the last plank in the evolutionary argument, not the first one, the final filling-in of the theory, providing the mechanism by which one species gave rise to another. The non-revolutionary nature of the Origin, to use Peter Bowler’s term, is shown by Secord’s chart in his book, which records that the Origin did not decisively outsell Vestiges until the twentieth century.79

  That said, the Origin did promote enormous opposition. Darwin himself realised that his theory of natural selection would prove the most contentious element in his argument and he was not wrong. John F. W. Herschel, a philosopher whom Darwin admired, called natural selection the ‘law of higgledy-piggledy’, while Sedgwick (who was both a divine and a scientist) condemned it as ‘a moral outrage’.80 Many of the favourable reviews of the Origin were lukewarm about natural selection: Lyell, for example, never accepted it fully, and described it as ‘distasteful’, while T. H. Huxley did not think it could be proved.81 In the late nineteenth century, while the theory of evolution was widely accepted, natural selection was ignored, and this was important because it allowed people to assume that evolution was ‘intended to develop toward a particular goal, just as embryos grew to maturity’. Viewed in this way, evolution was not the threat to religion it is sometimes made to appear.82 Indeed, the Origin had two chapters on the geographical distribution of living forms, making use of the geology and palaeontology reported above, and people had much less difficulty accepting this than the mechanism of selection. Vestiges had prepared part of the way. Ernst Mayr says the selection aspect of Darwin’s theory was not finally accepted until the evolutionary synthesis of the 1930s and 1940s.83 Many people simply thought that the implications of the Origin were immoral and remained convinced that the world was manifestly well-ordered–evidence for a divinity–and that Darwin’s ideas about accidental (‘higgledy-piggledy’) evolution could not produce such harmony. Darwinism was selfish and wasteful, they said, and a benevolent deity would never allow such a process. What was the Darwinian purpose of musical ability, or the ability to perform abstract mathematical calculations?84 Darwin, it should be said, was never entirely happy with the word ‘selection’, and many misunderstood how to interpret the term ‘fittest’. Several critics argued that Darwin’s method of theorising was unscientific because his theory could not be falsified.

  Darwin’s theory certainly had a major weakness. There was no account of the actual mechanisms by which inherited characteristics were passed on (‘hard heredity’). These were discovered by the monk Gregor Mendel in Moravia in 1865, but Darwin and everyone else missed their significance and they were not rediscovered and given general circulation until 1900. Until the rediscovery of Mendel, the theories of the German biologist Auguste Weismann attracted most attention, in particular the idea of ‘germ plasm’, which he developed out of cell theory. It will be remembered that cells had first been observed following the invention of the microscope, when they had been called ‘globules’ or ‘bubbles’ (see above, page 488). By the early nineteenth century, when significant advances were made in the design of microscopes, biologists, following Marie-François Xavier Bichat, recognised twenty-one categories of animal tissue and realised that they were all made up of cells, now shown to consist of more than their walls and to contain a sticky ‘substance of life’, baptised ‘protoplasm’ by J. E. Purkinje in 1839.85 The men who finally showed that all plants and animals were made up of cells were J. J. Schleiden (plants, 1838) and Theodor Schwann (animals, 1839). Weismann noted the nucleus in cells and gradually came to the view that the germ plasm does not consist of whole germinal cells but is concentrated in the rod-like structures in the nucleus which, because they stained differently, were called chromosomes. But even when Mendel was rediscovered it was not immediately apparent that his mechanism in a sense ‘completed’ Darwinism. This is because a debate was then raging as to whether selection, if it occurred, operated on continuous variation or only on disparate variation, that is, characteristics (such as blue or brown eyes) that varied discretely or, say, height, that varied continuously. Mendel himself seems to have chosen discrete characteristics (flower colour, whether seeds were wrinkled or not) because they were cleaner examples of the theory he was trying to prove and because he had his own rival theory to Darwin, namely that selection acted on hybrids, on intermediate forms. (Hybrids traditionally posed a theological problem, as forms intermediate between divinely created species.) The full significance of Mendelian genetics for Darwinian selection was not recognised until the 1920s.86

  Darwin didn’t stop with the Origin. No account of Darwinism can afford to neglect the Descent of Man. The idea of ‘progressionist evolution’ was everywhere in the nineteenth century, as we have seen, even in physics, with Kant and Laplace’s nebular hypothesis, the notion that the solar system has condensed from a vast cloud of dust under the influence of gravity.87

  This is one reason why, as the sciences of sociology, anthropology and archaeology began to emerge in the mid-nineteenth century, they were united in developing within a framework of progressionism. As early as 1861, Sir Henry Maine, in Ancient Law, had explored the ways in which the modern legal system had developed from the early practices found in ‘patriarchal family groups’.88 Other titles with a similar approach included John Lubbock’s Origin of Civilisation in 1870 and Lewis Morgan’s Ancient Society in 1877, though the most impressive, by far, was James Frazer’s Golden Bough, published in 1890. Early anthropologists had also been affected by the colonial experience: on several occasions attempts were made to educate colonised populations, the aim being to convert them to the ‘obviously’ superior European cultural practices. The fact that these attempts had all failed persuaded at least some anthropologists that there had to be ‘a fixed sequence of stages through which all cultures develop’.89 And it followed from this that one could not, artificially, boost one culture from an earlier stage to a later one. Lewis Morgan defined these major stages as savagery, barbarism and civilisation, a comforting doctrine for the colonial powers. The main ideas he discusses are the growth of the idea of government, the growth of the idea of the family, and the growth of the idea of property.90

  It was in this intellectual climate that archaeologists began conceiving the advances in regard to stone hand-axes that were described in the Prologue, when the ‘three-age system’ (of stone, bronze and iron) was introduced. We saw then that at first the idea of a ‘stone age’ of great antiquity met with fierce resistance. No one could accept that the earliest humans had co-existed with now-extinct animals, and it was only when Boucher des Perthes
discovered stone tools side-by-side with the bones of extinct animals in the gravel beds of northern France that ideas began to change. But then, roughly speaking in 1860, thanks in part to publication of the Origin, there was a rapid evolution in opinion, and the much greater antiquity of the human race was at last accepted. Charles Lyell finally acceded to the progressionist view of the earth, then collected a mass of evidence in favour of the new view, and synthesised it in Geological Evidences for the Antiquity of Man (1863).

  The extremely crude nature of the earliest stone tools convinced many that early man’s social and cultural circumstances were equally primitive, and this led John Lubbock to argue that there had been an evolution of society from savage origins. This was more shocking than it might seem because nineteenth-century religious thinkers still viewed modern man as degenerate as compared with Adam and Eve before the Fall. It was in his book Prehistoric Times (1865) that Lubbock first used the terms ‘Palaeolithic’ and ‘Neolithic’ to describe the transition from the Old to the New Stone Age, which he said could be distinguished by the change in use from chipped to polished stone, though more sophisticated variations were soon observed.91

  For many people, the crucial issue underlying the debate as to whether man was evolved from the apes revolved around the question of the soul. If man was, in effect, little more than an ape, did that mean that the very idea of a soul–the traditional all-important difference between animals and men–would have to be rejected? Darwin’s Descent of Man, published in 1871, tried to do two things at once: to convince sceptics that man really was descended from the animals and yet to explain what exactly it meant to be human–how humans had acquired their unique qualities.