The Science of Discworld II Page 12
How did human creativity arise? By now you won’t be surprised to learn that it came from stories. Let’s take a closer look at the current scientific view of human evolution, and fill in that gap between R-O-C-K and the space elevator.
An elf, observing Earth’s landmasses 25 million years ago, would have seen vast areas of forest. From the hills of northern India to Tibet and China, and down into Africa, these forests held a great variety of small apes, ranging from about half the size of chimpanzees to the size of gorillas. The apes were at home on the ground and in the lower branches of the forest, and they were so common that today we have many fossils of them. In addition, the Old World monkeys were starting to diversify in the upper levels of the forest. Earth was a Monkey Planet.
But also a Snake Planet, a Big Cat Planet, a Nematode Planet, an Alga Planet and a Grass Planet. Not to mention Plankton Planet, Bacterium Planet and Virus Planet. The elf might not have noticed that the African apes had produced several ground-dwelling kinds, not very different from the monkey-derived baboons. And it might also have failed to spot the presence of gibbons in the high branches, alongside the monkeys. These creatures were not particularly remarkable against a background of spectacular large mammals like rhinoceroses, a variety of forest elephants, bears. But we humans are interested in them, because they were our ancestors.
We call them ‘woods-apes’, dryopithecines. Some, known as Ramapithecus, were of lighter build – the jargon is ‘gracile’. Others, such as Sivapithecus, were big and strong – ‘robust’. The lineage of Sivapithecus was the one that led to orangutans. These early apes would have been shy, morose creatures like today’s wild apes, occasionally playful, but the adults would have been very belligerent and conscious of status within the group.
The forests inhabited by the woods-apes slowly dwindled as the climate cooled and dried, and grasslands – savannah country – took over. There were ice ages, but in the region of the tropics these did not reduce temperatures severely. However, they did change the patterns of rainfall. The monkeys thrived, producing many ground-living kinds like baboons and vervets, and the ape populations got smaller.
By ten million years ago, there were few apes left. There are almost no fossil apes from that period. It seems plausible that, as now and as previously, those apes that did still exist were forest creatures. Some, like today’s chimpanzees, gorillas and orangutans, were probably common in a few locations in the forests, but you’d have needed a lot of luck to find them. The observing elf might, even then, have put all of these apes on its Endangered List of Earth Mammals. Like very nearly all animal groups that had evolved, the forest apes were soon to be history rather than ecology. The common ancestor of humans and chimpanzees was, then, a not very remarkable ape that probably lived much as the different chimpanzees do now: some in flooded forest like today’s bonobos, some in rain-forest, and some in fairly open woodland grading into grasslands. The gorilla lineage separated from the other apes around this time.
At first, the elf would probably not have been very interested as – according to one of the two popular theories of human origins – a new kind of ape began to evolve a more upright stance than those of its relatives, lost its hair, and moved out on to the savannah. Many other mammals did the same; there was a new kind of living to be made on the great grass plains. Giant hyenas, massive wild dogs, lions and cheetahs made a good living from the vast herds of herbivores that lived on the productive savannah grasses; the giant pythons were probably originally savannah animals, too.
The story has been told many times, in many versions. And that’s just the point: we understand our ancestry through story. We wouldn’t be able to work out our ancestry from the fossils that we have discovered unless we’d learned just what clues to look for, especially since few fossil sites have enough evidence left.
The new ancestral plains ape saw the world differently. Judging from the behaviour of today’s chimpanzees, especially bonobos, it was a highly intelligent animal. We call their fossils southern apes, australopithecines, and there are hundreds of books that tell stories about them. They may have sojourned by the sea, doing clever things on beaches. Some certainly lived on lake margins. Today’s chimpanzees use stones to smash hard nuts open, and sticks to extract ants from nests; the australopithecines also used stones and sticks as tools, rather more so than their cousins the chimpanzees now do. They may have killed small game, as chimpanzees do. They probably used sexual behaviour to hang much of their pleasure on, like today’s bonobos, but most likely they were more gender-conscious and male-dominant. Like previous apes, they diverged into gracile and robust lines. The robust ones, called Anthropithecus boisi, or even a different genus Zinjanthropus (‘nutcracker man’) and other defamatory names, were vegetarians like today’s gorillas, and probably left no descendants in modern times.
This kind of split into gracile and robust forms, by the way, seems to be one of the standard patterns of evolution. Mathematical models suggest that it probably happens when a mixed population of big and small creatures can exploit the environment more effectively than a single population of medium-sized ones, but this idea has to be considered highly speculative until more evidence comes in. The zoological world was recently given a reminder of how common such a split is, and of how little we really know about the creatures of our own planet.
The animal involved could not have been better known, nor more appropriate to Discworld: the elephant.1 As every child learns at an early age, there are two kinds of elephant, two distinct species: the African elephant and the Indian elephant.
Not so. There are three species. Zoologists have been arguing for at least a century about what they thought was at most a subspecies of ‘the’ African elephant Loxodonta africana. The typical big, burly African elephant lives on the savannah. The elephants that live in the forest are shy, and difficult to spot: there is just one of them in the Paris zoo, for example. Biologists had assumed that because the forest elephants and the savannah elephants can interbreed at the edges of the forest, they could not be separate species. After all, the standard definition of a species, promoted by the evolutionary biologist Ernst Mayr, is ‘able to interbreed’. So they either insisted that there was just one species, or that ‘African elephant’ had a distinguished subspecies, the forest elephant Loxodonta africana cyclotis. On the other hand, zoologists who have had the good fortune to see forest elephants are in no doubt that they look very different from the savannah ones: they are smaller, with straighter, longer tusks, and round ears, not pointed ones. Nicholas Georgiadis, a biologist at the Mpala Research Centre in Kenya, has said: ‘If you see a forest elephant for the first time, you think, “Wow, what is that?”’ But because biologists knew, on theoretical grounds, that the animals had to be all the same species, the observational evidence was rejected as inconclusive.
However, in August 2001 a team of four biologists – Georgiadis, Alfred Roca, Jill Pecon-Slattery and Stephen O’Brien – reported in the journal Science their ‘Genetic evidence for two species of elephant in Africa’. Their DNA analysis makes it absolutely clear that the African elephant really does come in two distinct forms: the usual robust form, and a separate gracile form. Moreover, the gracile African elephants really are a different species from the robust ones. As different, in fact, as either African species is from the Indian one. So now we have the robust African plains elephant Loxodonta africana and the gracile African forest elephant Loxodonta cyclotis.
What of the belief that there could be only one species because of the potential for interbreeding? This particular definition of species is taking a hammering at the moment, and deservedly so. The main reason is a growing realisation that even when animals can interbreed, they may decide not to.
The story of the Third Elephant is not new: only the names have been changed. Before 1929 every zoologist ‘knew’ there was only one species of chimpanzee; after 1929, when the bonobos of the inaccessible swamps of Zaire were recognised as a second species,
2 it became obvious to many zoos that they had possessed two distinct chimpanzee species for years, but not realised it. Exactly the same story is now being played out with elephants.
As we’ve mentioned, Discworld recently revived interest in its fifth elephant, a story told, you will be surprised to hear, in The Fifth Elephant. According to legend, there were originally five elephants standing on Great A’Tuin and supporting the Disc, but one slipped, fell off the turtle, and crashed into a remote region of Discworld:
They say that the fifth elephant came screaming and trumpeting through the atmosphere in the young world all those years ago and landed hard enough to split continents and raise mountains.
No one actually saw it land, which raised the interesting philosophical question: when millions of tons of angry elephant come spinning through the sky, and there is no one to hear it, does it – philosophically speaking – make a noise?
And if there was no one to see it hit, did it actually hit?
There is evidence, in the form of vast deposits of fat and gold (the great elephants that support the world do not have ordinary bones), deep underground in the Schmaltzberg mines. However, there is a more down-to-Disc theory: some catastrophe killed off millions of mammoths, bison and giant shrews, and then covered them over. On Roundworld, there would be a good scientific test to distinguish the two theories: are the deposits of fat shaped like a crash-landed elephant? But there’s no point even in looking, on Discworld, because narrative imperative will ensure that they are, even if they were formed by millions of mammoths, bison and giant shrews. Reality has to follow the legend.
Roundworld has so far reached only its third elephant, although Jack hopes that some careful selective breeding might yet bring back a fourth: the pygmy elephant, which lived in Malta and was about the size of a Shetland pony. It would make a marvellous pet – except that, like many diminutive creatures, it would probably be rather bad-tempered. And the very devil to discourage from getting on the settee.
We are a gracile ape (not that you’d notice in some parts of the world, where many of us more closely resemble a robust hippopotamus). About four million years ago one gracile lineage of apes started to get bigger brains and better tools. Against all the rules of taxonomy we call this lineage, our lineage, Homo: it really should be Pan, because we are the third chimpanzee. We use this name because it is certainly our own lineage, and we prefer to think of ourselves as being enormously different from the apes. In this we could be right: we may indeed share 98 per cent of our genes with chimpanzees, but then, we share 47 per cent with cabbages. Our big difference from the apes is cultural, not genetic. Anyway, within the Homo lineage we again find gracile and robust stocks. Homo habilis was our gracile tool-making ancestor, but Homo ergaster and others went the vegetarian, robust way. If there actually is a yeti or a bigfoot, the best bet is a robust Homo. From Homo habilis’s success, a larger-brained Homo spread out over Africa, into Asia (as Peking Man) and Eastern Europe about 700 million years ago.
We have labelled one variety of these fossils Homo erectus. The visiting elf would certainly have noticed this fellow. He had several kinds of tools, and he used fire. He may even have possessed language, of a kind. What we have every reason to suspect that he did, that his ancestors and cousins only occasionally achieved, was to ‘understand’ his world and change it. Chimpanzees engage in quite a lot of ‘if … then’ activities, including ‘lying’: ‘if I pretend not to have seen that banana, I can come back and get it later when that big male won’t steal it from me’.
The young of this early hominid grew up in family groups where things were happening that were unlike anything anywhere else on the planet. Sure, there were lots of other mammal nests, packs and troupes, where the young were playing at being adult or just fooling around; nests were safe, and trial-and-error was rarely lethal, so the young could learn safely. But in the human lineage, father was making stone tools, grunting at his women about the children, about the cave, about putting more wood on the fire. There would be favourite gourds for banging, perhaps for fetching water, spears for hunting, lots of stones for tools.
Meanwhile, in Africa, another new lineage had arisen about 120,000 years ago, and spread; we call it ancient Homo sapiens, and it led to us. Its brain was even bigger, and in caves on the coast of South Africa it – we – had begun to make better tools, and to make primitive paintings on rocks and cave walls. Our population exploded, and we migrated. We reached Australia just over 60,000 years ago, and Europe about 50,000 years ago.
In Europe there had been a moderately robust Homo, the Neanderthal Homo sapiens neanderthalensis, a subspecies. Some anthropologists consider us to be a sister subspecies, Homo sapiens sapiens or, loosely speaking, ‘Seriously wise man’. Wow. The Neanderthals’ stone tools were well developed for various functions, but these particular hominids seem not to have been progressive. Their culture hardly changed over tens of thousands of years. But they seem to have had some kind of spiritual impulse, for they buried their dead with ceremony – or, at least, with flowers.
Our more gracile ancestors, the Cro-Magnon people, lived at the same time as the last of the Neanderthals, and there are many theories about what happened when the two subspecies interacted. Basically, we survived and the Neanderthals didn’t …
Why? Was it because we bashed them on the head more effectively than they bashed us? Did we outbreed them? Inbreed them? Squeeze them out into the ‘edge country’? Crush them with superior extelligence? We’ll put our own theory forward later in the book.
We don’t subscribe to the ‘rational’ story of human evolution and development, the story that has named us so pretentiously Homo sapiens sapiens. Briefly, that story focuses on the nerve cells in our brains, and says that our brains got bigger and bigger until finally we evolved Albert Einstein. They did, and we did, and Albert was indeed pretty bright, but nonetheless the thrust of that story is nonsense, because it doesn’t discuss why, or even how, our brains got bigger. It’s like describing a cathedral by saying ‘You start with a low wall of stones and as time passes you add more stones so that it gets higher and higher’. There’s a lot more to a cathedral than that, as its builders would attest.
What actually happened is much more interesting, and you can see it going on all around you today. Let’s look at it from the elf’s viewpoint. We don’t programme our children rationally, as we might set up a computer. Instead, we pour into their minds loads of irrational junk about sly foxes, wise owls, heroes and princes, magicians and genies, gods and demons, and bears that get stuck in rabbit-holes; we frighten them half to death with tales of terror, and they come to enjoy the fear. We beat them (not very much in the last few decades, but for thousands of years before that, for sure). We embed the teaching messages in long sagas, in priestly injunctions, and invented histories full of dramatic lessons; in children’s stories that teach them by indirection. Stand near a children’s playground, and watch (these days, check with the local police station first, and in any case be sure to wear protective clothing). Peter and Iona Opie did just that, many years ago, and collected children’s songs and games, some of them thousands of years old.
Culture passes through the whirlpool that is the child community without needing adults for its transmission: you will all remember Eeny-Meeny-Miny-Mo, or some other counting-out ritual. There is a children’s subculture that propagates itself without adult intervention, censorship, or indeed knowledge.
The Opies later collected, and began to explain to adults, the original nursery stories like Cinderella and Rumpelstiltskin. In late medieval times, Cinderella’s slipper had been a fur one, not glass. And that was a euphemism, because (at least in the German version) the girls gave the prince their ‘fur slipper’ to try on … The story came to us through the French, and in that language ‘verre’ can either be ‘glass’ or ‘fur’. The Grimm brothers went for the hygienic alternative, saving parents the danger of embarrassing explanations.
Rumpelstilt
skin was an interestingly sexual parable, too, a tale to programme the idea that female masturbation leads to sterility. Remember the tale? The miller’s daughter, put in the barn to ‘spin straw into gold’, virginally sits on a little stick that becomes a little man … The dénouement has the little man, when his name is finally identified, jumping in to ‘plug’ the lady very intimately, and the assembled soldiers can’t pull him out. In the modern bowdlerised version, this survives vestigially as the little man pushing his foot through the floor and not being able to pull it out, a total non sequitur. So none of those concerned, king, miller or queen, can procreate (the stolen first child has been killed by the soldiers), and it all ends in tears. If you doubt this interpretation, enjoy the indirection: ‘What is his name? What is his name?’ recurs in the story. What is his name? What is a stilt with a rumpled skin? Whoops. The name has an equivalent derivation in many languages, too. (In Discworld, Nanny Ogg claimed to have written a children’s story called ‘the Little Man Who Grew Too Big’, but, then, Mrs Ogg always believed that a double entendre can mean only one thing.)
Why do we like stories? Why are their messages embedded so deeply in the human psyche?
Our brains have evolved to understand the world through patterns. These may be visual patterns, such as the tiger’s stripes, or aural ones, like the howl of the coyote. Or smells. Or tastes. Or narratives. Stories are little mental models of the world, sequences of ideas strung like beads on a necklace. Each bead leads inexorably to the next bead; we know that the second little pig is going to get the chop: the world would not be working properly if it didn’t.
We deal not just in patterns, but also in meta-patterns. Patterns of patterns. We watch archer-fish shooting down insects with jets of water, we enjoy the elephant using its nose to acquire doughnuts from zoo visitors (less these days, alas); we delight in the flight of house-martins (there are fewer swallows to enjoy now) and the songs of garden-birds. We admire the weaver birds’ nests, the silk moths’ cocoons, the cheetahs’ speed. All these things are characteristic of the creatures concerned. And what is characteristic of us? Stories. So, by the same token, we enjoy the stories of people. We are the storytelling chimpanzee, and we appreciate the meta-pattern involved in that.