The Science of Discworld II - The Globe tsod-2 Read online

  The man who wrote this woke up every morning in a city that burned people alive and had still written this.

  '—what a piece of work is a man ... how noble in reason ... how infinite in faculty ... in form, in moving, how express and admirable ...'

  The Librarian was almost sobbing with laughter.

  'Nothing to laugh at, it's a perfectly valid point of view," said Rincewind. He shuffled the pages.

  'Who wrote this?' he said.

  'According to the flows of L-space, he is widely regarded as one of the greatest playwrights who ever lived,' said Hex, from the shelf.

  'What was his name?'

  'His own spelling is inconsistent,' said Hex, 'but the consensus is that his name was William Shakespeare.'

  'Does he exist on this world?'

  'Yes. In one of the many alternate histories.'

  'So not actually here, then?'

  'No. The leading playwright in this city is Arthur J. Nightingale.'

  'Is he any good?'

  'He is the best they have. Objectively, he is dreadful. His play King Rufus III is widely considered the worst play ever written.'

  'Oh.'

  'Rincewind!' bellowed the Archchancellor.

  The wizards were gathering in the circle. They had tied horseshoes and bits of iron to their staffs and had the look of high-order men prepared to kick low-order ass. Rincewind tucked the pages in his robe, picked up Hex and hurried over.

  'I'll just—' he began.

  'You're coming, too. No arguing. And the Luggage,' snapped Ridcully.

  'But—'

  'Otherwise we might have a talk about seven buckets of coal,' the Archchancellor went on.

  He knew about the buckets. Rincewind swallowed.

  'Leave Hex behind with the Librarian, will you?' said Ponder. 'He can keep an eye on Dr Dee.'

  'Isn't Hex coming?' said Rincewind, alarmed at the prospect of losing the only entity at UU that seemed to have a grasp on things.

  'There will be no suitable avatars,' said Hex.

  'He means no magic mirrors, no crystal balls,' said Ponder. 'Nothing that people expect to be magical. No people at all, where we're going. Put Hex down. We'll be back instantly, in any case.

  Ready, Hex?'

  For a moment the circle glowed, and the wizards vanished.

  Dr Dee turned to the Librarian.

  'It works!' he said. 'The Great Seal works! Now I can—'

  He vanished. And the floor vanished. And the house vanished. And the city vanished. And the Librarian landed in the swamp.

  8. PLANET OP THE APES

  'What a piece of work is a man! How noble in reason! How infinite in faculty! In form, in moving, how express and admirable! In action how like an angel! In apprehension how like a god!'

  But you wouldn't want to watch him eat, close up ...

  William Shakespeare was another key figure in the transition from medieval mysticism to post- Renaissance rationalism. We were going to mention him, but we had to wait for him to turn up in Roundworld.

  Shakespeare's plays are a cornerstone of our present Western civilisation[27]. They led us from a confrontation between aristocratism, barbarism and tradition-bound tribalism into real civilisation as we know it. And yet ... he seems to be a contradiction: uplifting sentiments in a barbarous age. That's because he was standing at a pivot point in history. The elves have been seeking something that will become human, and will interfere with Roundworld to make sure they get it. Humans are superstitious. But the human condition can also create a Shakespeare.

  Though not in this version of history.

  The elves aren't the only Discworld inhabitants that have interfered with Roundworld: the wizards have tried some 'uplift' of their own, in the sense of David Brin, and using the techniques of Arthur C. Clark near the end of The Science of Discworld, the apes of Roundworld are sitting in their cave, watching a manifestation from another dimension, an enigmatic black rectangular slab ... The Dean of Unseen University taps on it with his pointer, to attract attention, and chalks the letters R-O-C-K. 'Rock. Can anyone tell me what you do with it?' But all the apes are interested in is S-E-X.

  The next time the wizards look at Roundworld, the space elevator is collapsing. The planet's inhabitants are heading out into the universe on vast ships made from the cores of comets.

  Something very dramatic has happened between the apes and the space elevator. What was it?

  The wizards have no idea. They doubt very much it could have had much to do with those apes, who were very much The Wrong Stuff.

  In the first volume of The Science of Discworld, we explored no further. We left a gap. It was a tiny part of the historical record on the geological timescales that governed everything up to the ape, but rather a big gap in terms of changes to the planet. But now even the wizards are aware that the apes, unpromising material as they may have been, did in fact evolve into the creatures that built the space elevator and fled from a very dangerous planet in search of, as Rincewind would put it, a place where you are not hit on the head with rocks on a regular basis. And, apparently, a key step in their evolution was elvish interference.

  How did it actually happen on Roundworld? Here, the whole process took a mere five million years. One hundred thousand Grandfathers[28] ago, we and the chimpanzees shared a distant ancestor. The chimpanzeelike ancestor of Man was also the Manlike ancestor of the chimpanzee.

  To us, it would have looked astonishingly like a chimpanzee -but to a chimpanzee, it would have looked astonishingly like a human.

  DNA analysis shows, beyond any shadow of reasonable doubt, that our closest living relatives are chimpanzees: the ordinary ('robust') chimpanzee Pan troglodytes and the more slender ('gracile') bonobo Pan paniscus, often politically incorrectly called the pygmy chimpanzee. Our genomes have 98 per cent in common with both, leading Jared Diamond to refer to humans as 'the third chimpanzee' in a book of the same title.

  The same DNA evidence indicates that we and today's chimpanzees parted company, specieswise, those five million yean (100,000 Grandfathers) ago. That figure is debatable, but it can't be very far wrong. The gorillas split off a little earlier. The earliest fossils of our 'hominid'

  ancestors are found in Africa, but there are numerous later fossilised hominids from other parts of the world such as China and Java. The oldest known are two species of Australopithecus, each about 4-4.5 million years old. The Australopithecines had a good run: they hung around until about 1-1.5 million years ago, at which point they gave way to genus Homo: Homo rudolfensis, Homo habilis, Homo erectus, Homo ergaster, Hot heidelbergensis, Homo neanderthalensis, and finally us, Homo sapiens. And somehow another Australopithecine inserted itself into the middle of those Homos. In fact the more hominid fossils we find, the more complicated our conjectured ancestry becomes, and it now looks as if many different hominid species coexisted on the plains of Africa for most of the past five million years.

  Today's chimpanzees are quite bright, probably a lot brighter than the apes that the Dean tried to teach spelling to. Some remarkable experiments have shown that chimps can understand a simple version of language, presented to them as symbolic shapes. They can even form simple concepts and make abstract associations, all within a linguistic frame. They can't build a space elevator, and they never will unless they evolve considerably and avoid being killed for 'bush meat'.

  We can't build one either, but it might take no more than a couple of hundred years before the things are sprouting all along the equator. All you need is a material with enough tensile strength, perhaps some composite involving carbon nanotubes. Then you dangle cable from geostationary satellites, hang elevator compartments from them, equip them with suitable space elevator music ... after which, leaving the planet becomes entirely straightforward. The energy cost, hence the marginal financial cost, is near enough zero, because for everything that needs to go up, something else needs to come down. It could be moon rock, or platinum mined in the asteroid belt, or the a
stronaut that the person going up is due to replace on duty. The capital cost of such a project is enormous, though, which is why we're not in any great hurry right now.

  The big scientific problem in this connection is: how can evolution get so quickly from an ape that can't compete mentally with a chimpanzee to a godlike being that can write poetry as good as Shakespeare's, and has advanced so rapidly from that point that it will surely soon erect (drop) a space elevator? 100,000 Grandfathers hardly seems long enough, given that it took about 50 million Grandfathers[29] to get from a bacterium to the first chimpanzee.

  Something that dramatic needed a new trick. That trick was the invention of culture. Culture allowed any individual ape to make use of the ideas and discoveries of thousands of other apes. It let the ape collective acquire knowledge cumulatively, so that it didn't all get lost when its owner died. In Figments of Reality we coined the term 'extelligence' for this suite of tricks, and the word is beginning to become common currency. Extelligence is like our own personal intelligence, but it lives outside us. Intelligence has limits; extelligence is infinitely expandable. Extelligence lets us pull ourselves upwards, as a group, by our own mental bootstraps.

  The contradiction between Shakespeare's noble sentiments and the heads-on-spikes culture in which he lived is a consequence of his position as a very intelligent intelligence in a not-veryextelligent extelligence. Many individuals possessed the nobility to qualify for Shakespeare's praise, but their as yet rudimentary extelligence had not yet transmitted that nobility into the general culture. The culture was, or claimed to be, noble in principle -kings taking their authority from God Himself - but it was a barbarian style of nobility. And it was welded to a barbarian cruelty, the kings' means of self-preservation.

  There may be many ways to make intelligent creatures, and many more ways to knit them together into an extelligent culture. The crab civilisation in The Science of Discworld was doing fine until its Great Leap Sideways was clobbered by an inbound comet. We made that one up, but who knows what might have happened a hundred million years ago? All we know for sure or for a given value of 'sure', since even now a lot of our knowledge is guesswork -is that some things like apes turned into us. It takes a special kind of arrogance and blindness to extrapolate that story to the rest of the universe without wondering about alternatives.

  An important ingredient in our story was brains. Weight for weight, humans have far bigger brains than any other animal on the planet. The average human brain has a volume of about

  1,350 cubic centimetres, which is roughly three times as great as the brain of apes with the same size body as ours. Whale brains are bigger than ours, but whales are even bigger, so the amount of whale per brain cell is greater than the amount of human per brain cell. When it comes to the brains, quantity is less important than quality, of course. But a brain capable of really complicated things like carbon nanotube engineering and fixing dishwashers has to be fairly large, because the abilities of small brains are limited by lack of room to do anything interesting.

  We'll see shortly that brains alone are not enough. Nonetheless, without out brains, or adequate substitutes, you don't get very far.

  There are two main theories of human origins. One is rather dull and probably correct; the other is exciting and most likely wrong. Nevertheless, the second one has quite a lot going for it and is a better story, so let's take a look at them both.

  The dull, conventional theory is that we evolved on the savannahs. Roving groups of early apes trailed through the long grass, picking up whatever food - seeds, lizards, insects - they could find, much like today's baboons[30]. And as they did so, lions and leopards prowled through the long grass looking for monkeys. Those monkeys or apes that were better at spotting the telltale flicker of a big cat's tail, and finding a tree rather quickly, survived to have babies; those that performed poorly at such tasks did not. The babies inherited those survival skills, and passed them on to their babies.

  What these tasks need is computational power. Spotting a tail and finding a tree are pattern- recognition problems. Your brain needs to pick out the tail-shape from a background of similarly buff-coloured rocks and mud; it has to choose a tree that is tall enough, and climbable enough, without being too climbable, and it has to be able to do it fast. A capacious brain with a big memory (of past occasions when something hairy poked out from behind a rock, and of locations for climbable trees) can pick up the visual traces of a lion much more effectively than a small brain can. A brain whose nerve cells transmit signals to each other more quickly can analyse incoming sensory data and conclude 'lion' a lot faster than a slower brain can. So there was evolutionary pressure on the early apes and monkeys to develop bigger and faster brains. There was also evolutionary pressure on the lions to conceal themselves more effectively, so that those bigger and faster ape and monkey brains still didn't notice anything suspicious. So a predator- prey 'arms race' developed, a positive feedback loop that made both lions and apes far more effective in their ecological roles.

  That is the conventional story of human evolution. But there is another story, less orthodox, with two main sources.

  Human beings are very weird apes, indeed very weird animals altogether. They have extremely short fur, mostly just a downy covering. They walk upright on two legs. They have a layer of fat, all the year round. They mate face-to-face (often). They have exceptionally good breath-control; good enough to be able to speak. They weep and they sweat. They adore water, and can swim long distances. A newborn baby, dropped in a pool, can keep itself afloat: the ability to swim is instinctive. All these peculiarities led Elaine Morgan to write The Aquatic Ape in 1982. There she suggested a radical theory: that humans evolved not on the savannahs, surrounded by fierce predators, but on the beach. That explains the swimming, the upright stance (it's easier to evolve a two-legged gait if you are buoyed up by seawater), and the lack of hair (which causes problems when you swim, providing an evolutionary reason for it to disappear). In fact it can be argued that it explains all of the peculiarities of humans that we've just listed. The original scientific underpinnings of this theory were developed by Alister Hardy.

  In their 1991 The Driving Force Michael Crawford and David Marsh took the story one stage further, by added one extra ingredient. Literally. The most important thing that the beach provides is seafood. And the most important thing that seafood provides is 'essential fatty acids', which are a crucial ingredient in brains. In fact, nearly two-thirds of the human brain is made from them. Fatty acids are good for making membranes, and brains use electrical signals in membranes to compute. Myelin, in a membrane sheath surrounding nerve cells, speeds up the transmission of signals in the human nervous system by a factor of five or so. It takes a lot of essential fatty acids, then, to make a big, fast human brain, so it must have taken almost as much to make the brain of our distant ape ancestor. Oddly, though, our bodies cannot make those special fatty acids from simpler chemicals, like we make most complicated biochemicals that we need. We have to get the fatty acids, ready-made, from our food; that's why the word 'essential' is used to describe them. Even more oddly, there are few essential fatty acids out on the savannahs.

  They would exist only in living creatures, of course, but even there, they are fairly rare. The richest source of essential fatty acids is seafood.

  Perhaps all this explains why we want to spend so much time on the beach. But whatever the explanation, the ability to make big brain was one key step in our evolution away from our hairy, quadrupedal 100,000-fold great grandfather.

  Big brains, however, are not enough. What really matters is what you do with them. And what we managed to do was to play off one brain against another, so that over the millennia they got better and better at competing and communicating.

  Ape brains competing with lion brains leads to an arms race that improves both, but the arms race is fairly slow, because both brains are being used for very limited purposes as far as the competition goes. Ape brains c
ompeting with other ape brains gives the whole brain a workout, all the time, so the rate of evolution is likely to be much higher.

  For every species, the main competition comes from other creatures of the same species. This is reasonable; they're the ones that want exactly the same resources that you do. This opens the door to elvish interference, in our Discworld metaphor. The nasty side of human nature, which in extremes leads to evil, is inescapably bound up with the nice side. One very direct way to compete with your neighbour is to bash him on the head, hard.

  However, there are more subtle ways to gain evolutionary advancement, as we will see later. The elvish approach is crude, and ultimately self-defeating, for a sufficiently extelligent species.

  The possession of brains opens up new non-genetic ways to pass characteristics on to your children. You can give them a good start in life by moulding how their brains react to the outside world. The generic term for this kind of non-genetic transfer between the generations is privilege. There are numerous instances of privilege in the animal kingdom. When a mother blackbird provides yolk in her egg for the baby blackbird to feed from, that's privilege. When a cow provides milk for her calf, that's even more privilege. When a mother tarantula wasp provides a paralysed, living spider for her grubs to grow in, that's privilege.

  Humans have taken privilege to a qualitatively new level. Human parents invest an astonishing amount of time and effort in their children, and spend decades -entire lifetimes, in many ways looking after them. In conjunction with big brains, slowly getting bigger as each generation passes, privilege leads to two new tricks, learning and teaching. Those tricks feed off each other, and both require the best brain you can acquire[31].

  Genes are involved in building brains, and genes can perhaps predispose individuals to be unusually good at learning or teaching. However, both of these educational processes involve far more than mere genes: they take place within a culture. The child does not just learn from its parents. It learns from its grandparents, from its siblings, from its aunts and uncles, from the whole troupe or tribe. It learns, as all parents discover, to their dismay, from undesirable sources as well as authorised ones. Teaching is the attempt to transmit ideas from the adult brain to that of the child; learning is the child's attempt to insert those ideas into its brain. The system is imperfect, with a lot of garbled messages along the way, but despite its faults it is much faster than genetic evolution. That's because brains, networks of nerve cells, can adapt much more rapidly than genes can.