Darwin's Watch

by Terry Pratchett

  Then there are the quasi[1]-sciences like astrology, homeopathy, reflexology, and iridology, which simply can't work. They should be sharply distinguished from odd, often ancient practices like acupuncture, osteopathy and herbal treatments, which work sufficiently often but have a theoretical base that is poorly worked out in scientific terms. Many people are attracted by their homespun mix of myth and mysticism (which are all the more impressive because the treatment sometimes works), and feel that a modem scientific investigation would somehow spoil them. It would certainly poke some holes in the traditional rationalisations, but in all likelihood it would make the treatments even better. Whereas the quasi-sciences would be (indeed, already have been, not that everyone's noticed) demolished.

  To end that list, we add evolutionary biology, a very well-established set of models founded in the fossil record, chromosomes, and DNA, which explains similarities and differences among today's living creatures much more elegantly and effectively than its creationist or intelligent-design rivals. Nevertheless, a very large proportion of people - especially Christians in the American Mid-West, Muslims in fanatically Islamic cultures, and fundamentalist believers in general

  [1] Pronounced `crazy'.

  - deny that humans evolved. To them, their own brand of authority trumps the scientific evidence, or their `common sense' renders the whole concept laughable. `I ain't kin to no ape!' was the explanation given by a young schoolgirl at one of Jack's Life on Other Planets lectures, when the teacher asked her why she didn't believe in evolution.

  There is a general human propensity, of which much use is made in the Discworld books, to set up accepted, unexamined mental backgrounds. Mostly these result from the Make-a-Human-Being kits that each human culture inflicts on its members as they grow up through childhood and adolescence. Each of us is the result of a learning process, only a tiny fraction of which is overt `education' by professional teachers. The kit includes nursery rhymes, songs, stories, the personification of nursery animals (sly foxes, wise owls, industrious litter-collecting Wombles) and human roles from fabulous postman and princess up to crime-fighting Batman and Superman. All these have their place in the unexamined basis of our day-to-day thoughts and actions. A possible explanation for Princess Diana's undeniable popularity with the British public - indeed the world - is that she, unlike `real' royalty, had imbibed the popular impression of What Princesses Do as distinct from the authentically royal version. So she did what we had all learned that real princesses do, she looked and behaved like an icon, not like genuine royalty.

  Sophisticated human beings, citizens like us - and indeed like tribesmen and barbarians [1] in today's world, nearly all of whom have heard of Superman, Tarzan, Ronald MacDonald - all have this hotchpotch

  [1] This is a special usage devised by the anthropologist Lloyd Morgan in the 1880s, picked up by John Campbell Jr in an Analog editorial in the 1960s, then by Jack in The Privileged Ape: for tribal humans, everything is traditional, mandatory or forbidden; for barbarians, action is driven by honour, bravery, modesty, defiance of precedent; for citizens, some roles are tribal, some barbarian, we choose.

  of images, models, phobias, inspirations and villains. Our day-to-day experience gives us a self whose memory-train is a succession of scenes, thoughts, experiences, and passions, all painted a la Damasio with emotional tags that say `Great!', `Do This Again When I Can!' or `Avoid At All Costs!' when we recall them. But these sit upon a great mass of mostly unexamined structural human material, that labels us as Western Twentieth-Century Biologist or Ghetto Rabbi or Roman Centurion or Seventeenth-Century French Courtesan, or, for most people most of the time, Exploited Peasant.

  Each of those roles has a different set of emotional labels for money, for priests, for sex, for nakedness, for death, and for birth. Most people, until quite recently, underpinned that unexamined set of beliefs with a theist (personal, humanlike) God or gods, or a deist (Something Up There with Extraordinary Powers) god-structure, so the emotional tags on important memories have been strongly Godflavoured. When we remember them they may be sins, atonements, redemptions or trials. They may be mitzvahs (blessings) or revenges or charities. Religions, in bringing us into our cultures via their Makea-Christian or Make-a-Maya kit, put different-strength labels on, for example, human sacrifice, so that it has a whole host of associations in adult life. Our adult prejudices, and our scientific theories, go in on top of this crazy mishmash of historical errors, badly understood schooling, mathematics and statistics that barely make sense to us, God-stories of causality and ethics, and educational lies-to-children that permit the teacher to disengage his brain in response to children's questions.

  This mental mishmash is well illustrated by our changing attitudes to Mars. Mars was known to the ancients as a `wandering star', a planet; its reddish colour had bloody associations, so the Romans associated it with their god of war. It also acquired a connection with war in astrology, where the visible stars and planets all had to mean

  something. We're going to look at a lot of different associations with Mars,[1] as myth and rationality engaged with the red planet, as stories by the hundred employed Mars and Martians, and as the scientific picture of Mars changed over the centuries.

  We shouldn't ask `which is the true Mars?' We become larger humans by considering all of these aspects; from that stance there really isn't a true, real, objective planet for our minds to engage with usefully. Our simple, thin causal lines can't comprehend a real astronomical object, even a world which is actually out there so that we can see it. The `it' we see can be the disc whose apparent lines Giovanni Schiaparelli called 'canali', which excited Percival Lowell (whose grasp of Italian seems to have been slight, since the word means `channels') to see them as engineered canals. He wrote Mars as the Abode of Life, and this laid the foundation for the folk Mars of the twentieth century.

  Between the World Wars, everybody in the West, and many in the East, looked into the night sky and saw inimical Martians, a mental residue of that 1920s picture of a drying, dying Mars. The image was overlaid by the War of the Worlds picture of envious, grim, disgusting tripod Martians invading Earth (or at least England). There was a more romantic overlay for many of those out camping, or sleeping out under the stars: Barsoom. Edgar Rice Burroughs, familiar because of his Tarzan stories, invented a Mars whose dried-out seabeds were home to green Martian warrior hordes, six-legged centaur-like creatures whose egg-incubators were visited regularly. John Carter, an American ex-confederate army officer, had wished himself on to Mars, been captured by the green warriors but soon found himself married to a red Martian princess.[2]Stanley Weinbaum's A Martian Odyssey added more dimensions: the Martian called Tweel,

  [1] Not quite including the confectionery, which was the surname of the originator; he came to England from the USA, and invented M&Ms too. That stands for 'Mars and Mars'.

  [2] Also egg-laying. Jack, reading Burroughs when young, was disturbed by the idea of their marriage bed ...

  who made long hops and landed on his nose, the hypnotic predator that showed you your most desirable images, and attempts at a gosh-wow desert ecology. Then there were stories of Martians coming to Earth, pretending to be human ... and humans attempting to interact with a more or less mystical ancient Martian civilisation.

  The best known, perhaps the best crafted of these romanticmystical portrayals of crude, lumbering Earthmen, insensitive to the ethereal beauties of the Martian crystal cities, were Ray Bradbury's. In the 1950s and 1960s his tales were read by many outside the fantasy/SF world, and they appeared in widely read magazines like Argosy as well as in SF pulps in railway station bookstores. They laid the mystical ancient Martian foundation for Robert Heinlein to build the most potent of all these Martian tales, Stranger in a Strange Land. Michael Valentine Smith had been a foundling on Mars, brought up and trained in their culture by the ancient Martians. He came to Earth, founded a commune of friends -'Water Brothers'- and started a religion whose 'grokking the fullness
' of everyday events, from sex to science to swimming, spread to communities of readers. There was a tragic, well-publicised association with the murderous Manson killers, who had used this book as their mantra, but this didn't harm sales, and the ancient mystical Martians became the standard image.

  Then we learned that Mars has no atmosphere to speak of, that it is cold, dry, laden with frozen carbon dioxide, to the extent that the 'icecaps' were probably dry ice. Our machines visited Mars, looked for `life', and found strange chemistry because we inevitably asked the wrong questions. The `canals' died in the public mind, replaced by craters and gigantic volcanoes.

  We have now visited again, and it seems that ancient, wet Mars may have been a reality, there may be at least bacterial life forms under the sand ... Much is not yet clear, but what is clear is that our image of Mars has changed yet again.

  Each of us has a variety of associations with Mars. When we weave these many different interpretations and imaginations together, we become a different, wiser kind of creature. As for all of our different Marses ... well, those are toys of our imaginations, as we grok the red planet's fullness.

  If Mars seems a bit of a digression, consider those twin icons of evolution, the archaeopteryx and the dodo. In folk-evolutionary thinking, the archaeopteryx is the ancestor of all the birds, and the dodo is the bird that went extinct about 400 years ago. `As dead as a dodo.' Again, our thinking about these iconic creatures is heavily daubed with unchallenged assumptions, myths, and fictional associations.

  We mentioned archaeopteryx in Chapter 36 (`Running from Dinosaurs') of The Science of Discworld, second edition. We think of it as the ancestral bird because it is a dinosaur-like animal with birdlike feathers ... and it was the first one to be found. However, by the time of archaeopteryx there were plenty of genuine birds around, among them the diving bird Ichthyornis. Poor old archaeopteryx arrived on the scene far too late to be `the' bird ancestor.

  The recent amazing 'dinobird' discoveries in China - transitional creatures part way between dinosaurs and birds - have totally changed scientists' view of bird evolution. At some stage some dinosaurs started to develop feathers, though they couldn't then fly. The feathers had some other function, probably keeping the animal warm. Later, they turned out to be useful in wings. Some dinobirds effectively had four wings - two at the front, two at the back. It took a while before the standard `bird' body-plan settled down.

  As for the dodo - we all know what it looked like, right? Fat little thing with a big hooked beak ... Such a famously extinct creature must be well documented in the scientific literature.

  No, it's not. What we have is about ten paintings and half a stuffed specimen.[1]' We have more specimens of the archaeopteryx than we

  [1] Rajith Dissanayake, 'What did the Dodo look like?' Biologist 51 (2004), 165-8.

  do of the dodo. Why? The dodo went extinct, remember? And it did so before science really got interested in it. So few people recorded it, or studied it. It was there, not requiring special attention, and then it

  wasn't, and it was too late to start studying it. It isn't even certain what colour it was - many books say `grey', but it was more likely brown.

  Yet, we all know exactly what it looked like. How come? Because we all saw it illustrated by Sir John Tenniel in Alice's Adventures in Wonderland.

  Say no more.

  The great strength of Discworld narrative is that it makes fun of just those places where `education' has left us feeling a bit vulnerable: where we change the subject in the pub, or when our five-year-old asks us those probing questions. A running joke throughout the Science of Discworld series is what grammarians call 'privatives'. These are concepts that our minds seem quite happy with, even though a moment's thought shows that they're complete nonsense. Chapter 22 of The Science of Discworld discussed this notion, and we recap briefly.

  It is entirely normal to speak of `cold coming in the window' or `ignorance spreading among the masses'. The opposites of these concepts, heat and knowledge, are real, but we've dignified their absence with words that do not correspond to actual things. In Discworld, we find 'knurd', which is super-sober, as far from ordinary sober as drunk is in the alcoholic direction. There are jokes about the speed of dark, which must be faster than the speed of light because dark has to get out of the way. On Discworld, Death exists as a (perhaps the) major character, but on Roundworld that word refers only to the absence of life.

  People habitually label the absence of something with a word, instead of (or as well as) its presence: such words are the aforementioned privatives.

  Sometimes this habit leads to mistakes. The classic case was the label `phlogiston', the substance that appears to be emitted by burning materials. You can see it coming out as smoke, flame, foam ... It took many years to demonstrate that burning was an intake of oxygen, not the emission of phlogiston. During the intervening period, many people had demonstrated that when metals burned they got heavier, and had therefore argued that phlogiston had negative weight. These were clever people; they weren't being stupid. The phlogiston idea really did work - until oxygen supplanted its explanations, and alchemists suddenly found that the paths into rational chemistry were easier.

  Privatives are often very tempting. In What is Life?, a short book published in 1944, the great physicist Erwin Schrodinger asked precisely that question. At that time the Second Law of Thermodynamics - everything runs down, disorder always increases - was thought to be a fundamental principle about the universe. It implied that eventually everything would become a grey, cool soup of maximum entropy, maximum disorder: a `heat death' in which nothing interesting could happen. So in order to explain how, in such a universe, life could occur, Schrodinger claimed that life could only put off its individual tiny heat death by imbibing negative entropy, or 'negentropy'. Many physicists still believe this: that life is unnatural, selfishly causing entropy to increase more in its vicinity than it would otherwise do, by eating negentropy.

  This tendency to deny what is happening before our very eyes is part of what it is to be human. Discworld exploits it for humorous and serious purposes. By building Discworld flat, Terry pokes fun at flat-Earthers; rather, he recruits his readers into a `we all know the Earth is round, don't we?' fellowship. The Omnians' belief in a round Disc, in Small Gods, adds a further twist.

  We want to put what rational people are coming to believe into a general human context, so let's look at what everyone believes. In

  these days of fundamentalist terrorists we would do well to understand why a few people hold beliefs that are so different from the rational. These unexamined beliefs may be vitally important, because

  the ignorant people who espouse them think that they provide a good reason for killing us and our loved ones, even though they have never considered alternatives. People Who Know The Truth, by heredity or personal revelation or authority, are not concerned with logic or the validity of premises.

  Nearly everybody who has ever lived has been one of those.

  There have been a few sparse times and places - and we are hoping that the twenty-first century will host a few of them - in which onlookers are more ready to believe a disputant who is unsure, than one who is certain. But in today's politics, changing your mind in response to new evidence is seen as a weakness. When he was ViceChancellor at Warwick University, the biologist Sir Brian Follett remarked: `I don't like scientists on my committees. You don't know where they'll stand on any issue. Give them some more data, and they change their minds!' He understood the joke: most politicians wouldn't even realise it was a joke.

  In order to discuss the kinds of explanation and understanding that are going to have future values, we need at least a simple geography of where human beings pin their faiths now. What kinds of world picture are most common? They include those of the authoritarian theist, the more-or-less imaginative theist, the more critical deist, and various kinds of atheists - from Buddhists and the followers of Spinoza to those, including many scienti
sts and historians, who simply believe that the age of religion is behind us.

  Most human beings of the last few millennia seem to have been authoritarian theists, and we still have many of them in our world; perhaps they are still a majority. Does this mean that we must give intellectual 'equal time' to these views (plural, because they're all very different: Zeus, Odin, Jahweh ... ), or can we just dismiss them all with `I have no need of that hypothesis', as Laplace supposedly

  said to Napoleon. Voltaire, aware that God making man in His image meant that God's nature might be deduced from man's, thought it at least possible that God has mischievously misinformed us about reward and punishment. Perhaps sinners are rewarded by Heaven and saints are given a taste of Hell. Our view is that all the various authoritarian theists are the contemporary bearers of an extremely successful memeplex, a package of beliefs designed and selected through the generations to ensure its own propagation.

  A typical memeplex is the Jewish shema: `And these words ... you shall teach them to your children, muse on them when you get up and when you lie down ... Write them upon the doorposts of your house and upon your gates.' Like e-mail chain letters that threaten you with punishment if you fail to send them on to many friends, and with `luck' if you do send them on, the world's great religions have all promised pleasures for committed believers and transmitters, but pain for those who fail to adhere to the faith. Heretics, and those who leave the faith, are often killed by the faithful.