Chance is a Fine Thing

Climbing Mount Improbable by Richard Dawkins, Viking, £20, ISBN 0 670 85018 7

Richard Dawkins's Climbing Mount Improbable

John Cornwell

THERE'S a male spider Richard Dawkins writes about that woos its mate by attaching a string to her web and playing it like a jazzman. These strummings suppress her hunger and encourage her to sally forth along the thread for a sexual tryst. Nevertheless, the delay in her normal desire to feed sometimes wears off too soon, and the male ends up as her post-coital meal. But, Dawkins assures that all is well for "his genes are now safely stowed away inside the female".
"The world is well supplied with spiders," he adds, "whose male ancestors died after mating. The world is bereft of spiders whose would-be ancestors never mated in the first place."
With an eye for drama, and ample talent to instruct, this is vintage Dawkins. The anthropomorphism is rampant; so too is the ultra-reductionist, gene-centred evolutionary scenario; but hugely readable for all that.
Yet is readability enough?
A new book by Richard Dawkins has become a publishing event. The advance promotions, serial rights, personal profiles, place this new publication squarely in the genre of serious-but-popular-celebrity-author: like a new Le Carre' or perhaps a Martin Amis, Dawkins's work carries similar hints of "danger".
And good luck to him. Dawkins has done more than anyone, with the possible exception of Stephen J. Gould, to promote his field. But this popular pinnacle has its burdens, and (given the fact that we are talking science, and not fiction) responsibilities.
With a gap of less than a year since his last book, River Out Of Eden, a crucial question is whether the new offering, Climbing Mount Improbable, has anything new to say; indeed, whether there is much new here beyond the earlier books that brought him fame: The Selfish Gene and The Blind Watchmaker.
The parables-riveting biological narratives, enthralling as the Arabian Nights tales-continue to ring the changes. Yet the central message-that " DNA transcends the significance of the organism- a" remains the same. As he intimates with his spider story: organisms are merely vehicles for genes, which compete to leave more copies for the next generation. In other words, it is the information contained in genes that is of supreme consequence in the story of life on this planet.
At the heart of the book, however, is a gloss to this oft rehearsed thesis that amounts to a new emphasis rather than an original theme. How does chance operate in the Darwinian algorithm? The objection harks back to hoary contentions about a designer God in William Pale's Evidences, and well beyond. But, according to Dawkins, the problem of chance is also baffling to scientists and mathematicians.
Citing Chandra Wickramasinghe and Fred Hoyle, he asks how chance could give rise to the complex structure of a working enzyme. A typical enzyme, Dawkins notes,involves a mathematical sequence represented by a probability of 1 in 20200, a number far greater than the sum of the fundamental particles in the entire universe.
Dawkins's answer is implicit in the idea behind the book's title -Mount Improbable. One side of the mountain is a sheer cliff face with impossible overhangs; the other is a long but gentle grassy slope with well-worn footpaths. Evolution is not a story of sudden leaps but a long slow incline. "Darwinism", he tells us, "is not a theory of random chance. It is a theory of random mutation plus non-random cumulative natural selection".
Darwinism, he adds, solves the impossible odds "by breaking the improbability up into small, manageable parts, smearing out the luck needed, going round the back of Mount Improbable and crawling up the gentle slopes inch by million-year inch".
I am not sure that there are significant numbers of non-scientists (let alone distinguished physicists and mathematicians) who believe that Darwinism involves north face-of-the-Eiger type leaps of chance. But this brings us to another Dawkins ingredient.
Part of the dangerous fun of a Dawkins book is the gusto with which he kicks the tripes out of the Darwinian nay-sayers-usually the Creationists. Climbing Mount Improbable is no exception. "Only God would essay the mad task of leaping up the precipice in a single bound," he observes. "And if we postulate him as our cosmic designer we are left in exactly the same position as when we started."
Yet Mount Improbable, like River Out Of Eden before it, contains a significant variation on creation-bashing. In his last book Dawkins poured scorn on an anthropologist who refused to accept that Western science supersedes the value of other creation mythologies. The fellow was, I take it, talking metaphor and not biology.
Dawkins, adept at metaphor himself, seemed to be saying that he will have no truck with creation narratives and images (whatever the genre) that fail to take their cue from the empirical sciences. Similarly, in Mount Improbable, he duffs up a hapless "literary dilettante" who had the temerity to deliver a lecture on the subject of The Fig. "Not a botanical lecture," declares Dawkins witheringly, but "a literary one ... the fig in literature, the fig as metaphor." This kind of thing, comments Dawkins, "is the stock-in-trade of a certain kind of literary mind, but it provokes me to literal-mindedness".
The inference, extraordinary as it is plain, is that people should stop wasting their time with literary criticism for in botanical science "there is genuine paradox and real poetry lurking in the fig with subtleties to exercise an inquiring mind and wonders to uplift an aesthetic one". This targeting of his literary and anthropological colleagues is difficult to take seriously, and more tellingly, it diverts attention from his real peer group opponents in biology where a crucial debate is in progress. On the one hand, there are the ultra-Darwinians (theoretical geneticists) such as himself, John Maynard Smith and George Williams; on the other, the "naturalists" who emphasise the importance of large-scale systems-social systems, ecosystems, species, such as Gould, Dick Lewontin, Steven Rose and Niles Eldredge.
And it is precisely within this debate that serious questions have been raised that deserve answers. Lewontin reminds us that consciousness-which gives rise to history, personhood, society-is an aspect of the structure of organisms and not genes. While Rose charges that Dawkins's biological reductionism gives comfort to neurogenetic determinism, and the ideological Right-no such thing as society, only the individual.
In this sense I feel that Dan Dennett's last book, Darwin's Dangerous Idea, leaves Dawkins in the shade. Dennett is variously and continuously prepared to cite the work of those who challenge his premises. On the question of chance and design, for example, he cites Stuart Kauffman, who finds a mysterious propensity towards order, large scale and small scale, in the realms of both the living and the non-living universe, as well as in mathematics. Dennet may not agree with Kauffman, but the lay reader is left with an impression of the dynamic and pluralistic nature of current expository philosophy of science, as it applies to evolutionary theory.
It may seem churlish to find fault with a book that so eloquently expounds the subtle complexities and mysteries of biology. But for me, Dawkins's work-and I would include his new role as Professor of Public Understanding of Science at Oxford-would lose nothing, and gain much, by an acknowledgement that biology, at the level he has chosen to write about it, does not speak with a single and oracular voice.

F John Cornwell is senior research fellow, and director of the Science and Human Dimension Project; at Jesus College, Cambridge. His last book Nature's Imagination is published by Oxford University Press.

Fatal attractions

Martin Brookes thinks scientists are as easily lured by irresistible ideas as anyone else
BIOLOGIST and writer Richard Dawkins is the inaugural holder of the Charles Simonyi chair in the public understanding of science at the University of Oxford. Since taking up his new position in January, he has maintained a highly publicised campaign against scientific illiteracy. Some of his most vitriolic attacks have been reserved for the pseudosciences-astrology in particular.
Dawkins considers astrology to be a primitive myth that passed its sell-by date centuries ago. Its major protagonists he describes as modern-day sophists who hold a gullible public to ransom with false and banal predictions about personal destinies. Although it is easy to sympathise with Dawkins's frustrations, his approach is unlikely to win over the agnostics to his rationalist world view.
He sees astrology, like religion, as a highly successful "meme"-a word he coined twenty years ago in his book The Selfish Gene. A meme is the cultural equivalent of a gene. Successful memes are those ideas or beliefs which are good at passing on copies of themselves to subsequent generations. Some ideas spread because they are true, others merely because they are psychologically appealing.
Almost by definition, religion is scientifically untestable: it is simply a matter of faith. Astrology, however, makes predictions that can, in principle, be scientifically tested. Carl Jung, the Swiss psychologist and philosopher, was a great believer. Using data on marriages and divorce, he claimed to show that successful marriages were more likely between individuals whose star signs were astrologically matched. Even if his observations were true (they were later dismissed as 'statistically inaccurate"), it is a giant leap to go from a correlation to a causal link. Jung offered no explanation as to how the relative positions of the stars and planets could affect the behaviour of individuals on Earth. Until hypotheses are put forward and experiments are devised to test them, sceptics will always dismiss such associations, where they exist, as being due to something more obvious and trivial.
The extent to which the psychological impact of an idea can determine its success should not be underestimated. As scientists we may like to think of ourselves as the torchbearers for all that is objective, rational and true, but we are human beings too. We can find the intrinsic lure of an idea irresistible, just like everyone else.
In order to make sense of the world, scientists invent testable hypotheses that can be supported or falsified by experiment. In an ideal world, scientists would like to pursue generalised theories with high predictive power. Though nature is often reluctant to submit to such unifying theories, the search for them provides a fertile environment for the spread of attractive ideas with weak empirical support.
As a case in point, there has been endless talk in both the scientific and popular press recently about body symmetry. In animals, including humans, evidence suggests that the more symmetrical an individual's body is, the more attractive it is and the greater its mating success. In other words, symmetry and attractiveness appear to go hand in hand. Current explanations for this are based on the idea that the degree of symmetry is an outward expression of an individual's ability to resist stresses, such as disease, during their development. So if resistance to stress is inherited, choosing a symmetrical partner to mate with may be a good way of increasing the Darwinian fitness of your offspring.
Though it is entirely plausible, evidence in support of this hypothesis is, at best, ambiguous. Nevertheless, studies of symmetry have mushroomed recently. Despite equivocal evidence as to what these associations (or the lack of them) may actually mean, prominent scientists are pursuing them with an evangelical zeal. The symmetry meme is up and running.
It's easy to see why such studies have become so popular. Symmetry can be measured without the need for high-tech apparatus, making it cheap to study-an important factor given the current state of science funding. Scientifically, it is attractive because it appears to offer a short cut to measuring the Darwinian fitness of individuals-a notoriously difficult thing to measure, but crucial to an understanding of evolutionary processes.
Once a persuasive idea has established itself, it can prove extremely resistant, even when confronted with contrary scientific evidence. There are many symmetry studies which have not shown the expected associations. The meme is so strong that these studies are often perceived as uninteresting, or experimentally flawed. Reticence on the part of researchers and editors of scientific journals means that conflicting studies have not been publicised.
Future experiments may uncover more about the intricate relationship between symmetry, genetics and attractiveness. Until then, we should be wary that the appeal of such ideas does not overtake the factual evidence to support them. The late philosopher of science Karl Popper once remarked that science must begin with myths, and the criticism of myths. As a scientist, I am right behind Dawkins's assertion that astrology is a primitive myth. But if we are to practise what we preach, then scientists themselves should also be wary of stars in their eyes.
Martin Brookes is a freelance writer. [New Scientist 12 Oct 96 ]





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