talked of animals that survived ‘being organised spontaneously in a fitting way; whereas those which grew otherwise perished and continue to perish’. It was, had Empedocles only known it, probably the best idea he ever had, though he never seems to have followed it through. Darwin was rediscovering an idea.
Gould’s swerve
Why was it even necessary, nearly 150 years after Darwin set out his theory, for Judge Jones to make the case again? This remarkable persistence of resistance to the idea of evolution, packaged and repackaged as natural theology, then creation science, then intelligent design, has never been satisfactorily explained. Biblical literalism cannot fully justify why people so dislike the idea of spontaneous biological complexity. After all, Muslims have no truck with the idea that the earth is 6,000 years old, yet they too find the argument from design persuasive. Probably fewer than 20 per cent of people in most Muslim-dominated countries accept Darwinian evolution to be true. Adnan Oktar, for example, a polemical Turkish creationist who also uses the name Harun Yahya, employs the argument from design to ‘prove’ that Allah created living things. Defining design as ‘a harmonious assembling of various parts into an orderly form towards a common goal’, he then argues that birds show evidence of design, their hollowed bones, strong muscles and feathers making it ‘obvious that the bird is product of a certain design’. Such a fit between form and function, however, is very much part of the Darwinian argument too.
Secular people, too, often jib at accepting the idea that complex organs and bodies can emerge without a plan. In the late 1970s a debate within Darwinism, between a predominantly American school led by the fossil expert Stephen Jay Gould and a predominantly British one led by the behaviour expert Richard Dawkins, about the pervasiveness of adaptation, led to some bitter and high-profile exchanges. Dawkins thought that almost every feature of a modern organism had probably been subject to selection for a function, whereas Gould thought that lots of change happened for accidental reasons. By the end, Gould seemed to have persuaded many lay people that Darwinism had gone too far; that it was claiming a fit between form and function too often and too glibly; that the idea of the organism adapting to its environment through natural selection had been refuted or at least diminished. In the media, this fed what John Maynard Smith called ‘a strong wish to believe that the Darwinian theory is false’, and culminated in an editorial in the Guardian announcing the death of Darwinism.
Within evolutionary biology, however, Gould lost the argument. Asking what an organ had evolved to do continued to be the main means by which biologists interpreted anatomy, biochemistry and behaviour. Dinosaurs may have been large ‘to’ achieve stable temperatures and escape predation, while nightingales may sing ‘to’ attract females.
This is not the place to retell the story of that debate, which had many twists and turns, from the spandrels of the Cathedral of San Marco in Venice to the partial resemblance of a caterpillar to a bird’s turd. My purpose here is different – to discern the motivation of Gould’s attack on adaptationism and its extraordinary popularity outside science. It was Gould’s Lucretian swerve. Daniel Dennett, Darwin’s foremost philosopher, thought Gould was ‘following in a long tradition of eminent thinkers who have been seeking skyhooks – and coming up with cranes’, and saw his antipathy to ‘Darwin’s dangerous idea as fundamentally a desire to protect or restore the Mind-first, top–down vision of John Locke’.
Whether this interpretation is fair or not, the problem Darwin and his followers have is that the world is replete with examples of deliberate design, from watches to governments. Some of them even involve design: the many different breeds of pigeons that Darwin so admired, from tumblers to fantails, were all produced by ‘mind-first’ selective breeding, just like natural selection but at least semi-deliberate and intentional. Darwin’s reliance on pigeon breeding to tell the tale of natural selection was fraught with danger – for his analogy was indeed a form of intelligent design.
Wallace’s swerve
Again and again, Darwin’s followers would go only so far, before swerving. Alfred Russel Wallace, for instance, co-discovered natural selection and was in many ways an even more radical enthusiast for Darwinism (a word he coined) than Darwin himself. Wallace was not afraid to include human beings within natural selection very early on; and he was almost alone in defending natural selection as the main mechanism of evolution in the 1880s, when it was sharply out of fashion. But then he executed a Lucretian swerve. Saying that ‘the Brain of the Savage [had been] shown to be Larger than he Needs it to be’ for survival, he concluded that ‘a superior intelligence has guided the development of man in a definite direction, and for a special purpose’. To which Darwin replied, chidingly, in a letter: ‘I hope you have not murdered too completely your own and my child.’
Later, in a book published in 1889 that resolutely champions Darwinism (the title of the book), Wallace ends by executing a sudden U-turn, just like Hume and so many others. Having demolished skyhook after skyhook, he suddenly erects three at the close. The origin of life, he declares, is impossible to explain without a mysterious force. It is ‘altogether preposterous’ to argue that consciousness in animals could be an emergent consequence of complexity. And mankind’s ‘most characteristic and noble faculties could not possibly have been developed by means of the same laws which have determined the progressive development of the organic world in general’. Wallace, who was by now a fervent spiritualist, demanded three skyhooks to explain life, consciousness and human mental achievements. These three stages of progress pointed, he said, to an unseen universe, ‘a world of spirit, to which the world of matter is altogether subordinate’.
The lure of Lamarck
The repeated revival of Lamarckian ideas to this day likewise speaks of a yearning to reintroduce mind-first intentionality into Darwinism. Jean-Baptiste de Lamarck suggested long before Darwin that creatures might inherit acquired characteristics – so a blacksmith’s son would inherit his father’s powerful forearms even though these were acquired by exercise, not inheritance. Yet people obviously do not inherit mutilations from their parents, such as amputated limbs, so for Lamarck to be right there would have to be some kind of intelligence inside the body deciding what was worth passing on and what was not. But you can see the appeal of such a scheme to those left disoriented by the departure of God the designer from the Darwinised scene. Towards the end of his life, even Darwin flirted with some tenets of Lamarckism as he struggled to understand heredity.
At the end of the nineteenth century, the German biologist August Weismann pointed out a huge problem with Lamarckism: the separation of germ-line cells (the ones that end up being eggs or sperm) from other body cells early in the life of an animal makes it virtually impossible for information to feed back from what happens to a body during its life into its very recipe. Since the germ cells were not an organism in microcosm, the message telling them to adopt an acquired character must, Weismann argued, be of an entirely different nature from the change itself. Changing a cake after it has been baked cannot alter the recipe that was used.
The Lamarckians did not give up, though. In the 1920s a herpetologist named Paul Kammerer in Vienna claimed to have changed the biology of midwife toads by changing their environment. The evidence was flaky at best, and wishfully interpreted. When accused of fraud, Kammerer killed himself. A posthumous attempt by the writer Arthur Koestler to make Kammerer into a martyr to the truth only reinforced the desperation so many non-scientists felt to rescue a top–down explanation of evolution.
It is still going on. Epigenetics is a respectable branch of genetic science that examines how modifications to DNA sequences acquired early in life in response to experience can affect the adult body. There is a much more speculative version of the story, though. Most of these modifications are swept clean when the sperm and egg cells are made, but perhaps a few just might survive the jump into a new generation. Certain genetic disorders, for example, seem to manifest themselves
