Evolution

by Stephen Baxter

  Some of the adults had brought volcanic pebbles from the nearby stream. Now men and women began briskly to knap the pebbles, their hands working rapidly, their fingers exploring the stone. The tools emerged from the stone without real conscious effort — this was a skill that was already ancient, embedded in a self-contained section of a rigidly divided mind — and within a few minutes they had fashioned crude but serviceable choppers and cutting flakes. As quickly as each tool was finished its manufacturer fell on the eland.

  The skin was sliced open from anus to throat, and pulled briskly off the carcass. The hide was discarded; nobody had thought up a use for animal skins, not yet. Now the carcass was briskly butchered, with the fine stone blades slicing into joints to separate the limbs from the body, through the rib cage to expose the soft, warm organs within, and then into the meat itself to separate it from the bone.

  It was a fast, efficient, almost bloodless affair, a skillful butchering born of generations of ancestral learning. But the butchers did not work together. Though they deferred to Brow, allowing him to take the prime cuts and to extract the heart and liver, they competed as they scavenged the corpse, grunting and prodding at each other. Despite the tools in their hands, they worked at the eland like a pack of wolves.

  Few of the women fought for the meat. Their unglamorous scavenging in the acacia grove and elsewhere had been successful today, and their bellies, and those of their children, were already full of figs, grewia berries, grass shoots, roots — fruits abundant in these dry lands that did not require much preparation before eating.

  When most of the meat had been taken from the eland’s bones, the bargaining began in earnest. Brow stalked among the men with a blade in one hand and a mighty slab of haunch in the other. He sliced off chunks of the meat and handed them to some of the men — and not to others, who turned away as if it were unimportant, but who would later try to snatch bits of the best meat from the rest. It was all part of the endless politicking of the men.

  Then Brow walked among the women, handing out bits of meat like a visiting king. When he reached Calm, he paused, his erection proud, and sliced off a large and succulent slab of eland haunch. Sighing, she accepted it. She ate some of it quickly, then put the rest to one side, close to her infant, who was asleep in a nest of dead grass. Then she lay on her back and opened her thighs, and held up her arms to accept Brow.

  Brow hadn’t gone hunting primarily to bring food to his people. Large game provided maybe only a tenth of the group’s intake; the vast majority of it came from the plants, nuts, insects, and small game foraged by the women and older children as much as by the men. Large game was a useful emergency food supply in hard times — drought or flood, perhaps, or in tough winters. But hunting was useful to the hunter in a whole range of ways. With his eland meat Brow was able to reinforce his political position among the men — and buy access to the women, which was ultimately the only purpose of his endless battle for dominance.

  With their greater intelligence, tall, hairless bodies, and rudimentary language, these were the most human creatures yet to exist. But much of the way they ran their lives would have been immediately familiar to Capo. Brow’s ancestors had fallen into this social pattern — of males fighting for dominance, of females linked along bloodlines, of hunting to buy favors — far back in time, long before Capo’s fateful decision to leave his pocket of forest. There were other ways for primates to live, other kinds of societies that could be imagined. But once the pattern had been set, it was all but impossible to break.

  Anyhow the system worked. The food was shared out; the peace was kept. One way or another, most people got fed.

  When Brow was done Calm wiped her thighs with a leaf and returned to the meat. She used a discarded stone flake to slice it up, and handed some to her mother — who was too old to be of interest to Brow — and gave the rest to Far, who fell on it eagerly.

  And later, as the light faded, Brow approached Far herself. She saw him as a tall, beefy silhouette against the sky’s fading red purple. Most of his eland meat was gone now, but she smelled its blood on him. He carried a foreleg bone. He crouched down before her, sniffing her curiously. Then he slammed the bone against the rock, cracking it. She could smell its delicious marrow, and her mouth filled with saliva. Without thinking she reached for the bone.

  He held it back, making her come closer.

  As she approached she could smell him more clearly: the blood, the dirt, the sweat, and a lingering stink of semen. He relented and gave her the bone, and she pushed her tongue into the marrow, sucking at it eagerly. As she ate he put his hand on her shoulder and ran it down her body. She tried not to flinch when he explored her small breasts, pulling her nipples. But she squealed when his probing fingers parted her legs. He drew back his hand and sniffed her scent. Then, evidently deciding she had nothing to sell him, he grunted and moved away.

  But he left her the marrow. Eagerly she devoured it, finishing most of it before the bone was stolen from her by an older woman.

  The light leached quickly out of the sky. All across the savannah the predators called, marking their bloody kingdoms in their ancient way.

  The people gathered on their island of rock. All of them felt a shiver of apprehension as they huddled together — children at the center, adults with their backs facing outward — and prepared to enter a long night of unbroken darkness. They ought to be safe here, in this inhospitable place: any ambitious predator would have to leave the ground and clamber up here, where it would face smart, large, and armed hominids. But there was no guarantee. There was a saber-tooth around called dinofelis, an ambush predator like a stocky jaguar, that specialized in killing hominids. Dinofelis could even climb trees.

  As the darkness fell, the people went about their business. Some fed. Some tended to their bodies, digging dirt out of toenails or fingering blisters. Some worked on tools. Many of these activities were repetitive, ritualistic. Nobody was truly thinking about what they were doing.

  Some groomed: mothers with infants, siblings, mates, women, and men reinforcing their subtle alliances. Far worked on her mother’s dense head hair, teasing out knots and pulling it into a kind of plait. Even now hair needed a lot of work — it would tangle, mat, and attract lice, all of which needed fixing.

  These people were the only species of mammal whose heavy hair was not self-maintaining; the spectacular tonsorial plumage of some monkeys, for instance, just grew that way. Far’s hair even needed cutting regularly. But people’s hair had developed that way because they needed something to groom. Out here on the savannah it paid to be part of a large group, and the group needed social mechanisms to hold itself together. There wasn’t time now for the old ape ways, the elaborate full-body grooming indulged in by Capo and his ancestors. Anyway you couldn’t groom skin that had become bare so it could sweat. But still, in this primitive hairdressing, they retained links with their heritage.

  The grammar of the people as they went about their diverse activities was not like that of a human group. In the gathering dark they huddled together for protection, but there was no real sharing. There was no fire, and nothing like a hearth, no central focus. They looked human, but their minds were not like humans’.

  Just as in Capo’s time, their thinking was rigidly compartmented. The main purpose of consciousness was still to help people figure out what was in each others’ minds: They were only truly self-aware in the human sense when dealing with each other. The boundaries of awareness were much more narrow than in human minds; there was much beyond, out in the darkness, that they did essentially without thinking about it. Even those making tools or working on food did so wordlessly, their hands working impulsively, with no more conscious control than lions or wolves. Their awareness at such times was rolling, fleeting. They made tools as unconsciously as humans would walk or breathe.

  However, human or not, a soft susurrus of language washed over the group. The talking was among the mothers and infants, the groomers, and th
e couples. There wasn’t much information being passed on; much of the talk was little more than sighs of pleasure, like the purring of cats.

  But their words sounded like words.

  People had had to learn to communicate with equipment designed for other tasks — a mouth intended for eating, ears intended to listen for danger — now jury-rigged for a new use. Their bipedalism had helped: the repositioning of their larynxes and changes in the pattern of breathing improved the quality of the sounds they could make. But to be useful, sounds had to be identifiable quickly and unambiguously. And the ways the hominids could achieve that were limited by the nature of the equipment they had to use. As people listened to each other, and imitated and reused useful noises, phonemes — the sound content of the words, the basis of all language — had selected themselves, driven by communicative necessity and engineering limitations.

  But there was nothing yet like grammar — no sentences — and certainly no narratives, no stories. And the main purpose of talking right now wasn’t to pass on information. Nobody talked about tools or hunting or food preparation. Language was social: It was used for commands and demands, for blunt expressions of joy or pain. And it was used for grooming: Language, even without much content, was a more efficient way to establish and reinforce relations than picking ticks out of pubic hair. It even worked to “groom” several people at once.

  A lot of the evolution of language, in fact, had been driven by mothers and infants. Right now the ancestors of Demosthenes and Lincoln and Churchill spoke nothing much more than motherese.

  And the children didn’t talk at all.

  The minds of the adults were about equivalent in complexity to a five-year-old human’s. Their children were not capable of speech — nothing beyond chimplike jabbers — until they reached adolescence. It had only been a year or two since the adults’ words had made any sense to Far, and the Brat, at seven, couldn’t talk at all. The kids were like apes born to human parents.

  As the light died, so the group settled toward sleep.

  Far huddled against her mother’s legs. The ending day became just one of a long chain that stretched back to the beginning of her life, days dimly remembered, only vaguely linked. In the darkness she imagined running in the blinding brightness of day, running and running.

  She had no way of knowing that this was the last time she would fall asleep close to her mother.

  II

  A million years ago, tectonic drift, slow but relentless, had caused North and South America to collide, and the isthmus of Panama was formed.

  In itself it seemed a small event, Panama an inconsequential sliver of land. But, as with Chicxulub, this region had once more become the epicenter of a worldwide catastrophe.

  Because of Panama, the old equatorial flows through the Americas — the last trace of the Edenic Tethys current — had been cut off. Now the only Atlantic currents were the huge interpolar flows, great conveyor belts of cold water. The worldwide cooling intensified drastically. The scattered ice caps covering the northern ocean merged, and glaciers spread like claws over the northern landmasses.

  The Ice Ages had begun. At their greatest extent the glaciers would cover more than a quarter of all Earth’s surface; the ice would reach as far as Missouri and central England. Much was immediately lost. Where the glaciers passed, the land was scraped clean — down to the bedrock, which was itself pulverized and ground to dust — leaving a legacy of mountains with scored flanks, polished surfaces, scattered boulders, and gouged-out valleys. There had been no significant glaciation on Earth for two hundred million years; now a legacy of rocks and bones dating back deep into the age of the dinosaurs was comprehensively destroyed.

  On the ice itself, nothing could live: nothing. Below the ice, great impoverished belts of tundra spread. Even in places far from the ice, like the equatorial regions of Africa, changes in wind patterns intensified the aridity, and vegetation shrank back to the coasts and river valleys.

  The cooling was not a uniform trend. The planet tipped and bobbed in its endless dance around the sun, subtly shifting its degree of tilt, its inclination, and the fine-tuning of its orbit. And with each cycle the ice came and went, came and went; ocean levels fluctuated like the pumping of a heart. Even the land, compressed under kilometers of ice or released by its melting, rose and fell like a rocky tide.

  Sometimes the climate shifts could be savage. Within a single year the amount of snowfall in an area could double, the average temperature fall by ten degrees. Faced with such chaotic oscillations, living things moved, or died.

  Even the forests marched. Spruce proved a fast migrant, followed by pine, capable of marching at a kilometer every two years. The great chestnuts, massive trees with heavy seeds, could manage a pace of a hundred meters a year. Before the Ice Age the animals of the middle latitudes of the northern hemisphere had been a rich mixture of fleet grazers like deer and horses, giant herbivores like rhinos, and fast-running carnivores like lions and wolves. Now the animals were driven south in search of warmth. Populations of animals from different climatic zones were mixed up and forced to compete in fast-changing ecological arenas.

  But some creatures began to adapt to the cold, to exploit the food supplies that still existed at the feet of the ice sheets. Many animals grew thick fur and layers of fat — large animals, like rhinos, and smaller animals, like foxes and horses and cats. Others began to take advantage of the huge temperature swings between the seasons. They migrated, moving north in the summer and south in the winter; the plains became a huge tidal wash of life, great mobile communities patiently stalked by predators.

  There had been a catastrophe of mixing in the Americas. The two continents, north and south, had been separated since the shattering of Pangaea some one hundred and fifty million years ago. The fauna of South America had evolved in isolation, and was dominated by marsupial mammals and ungulates. There were marsupial “wolves” and saber-toothed “cats”; there were ungulate “camels” and trunked “elephants,” and giant ground sloths that could weigh three tons and stood six meters tall when they stood up to browse on palm leaves. There were still glyptodonts, not so dissimilar from the huge armored beast that had terrified Roamer, and the top predators were giant flightless birds, just as in archaic times. This exotic assemblage had been left alone to develop — though it was supplemented from time to time by waifs, brought by rafting or temporary bridges, like Roamer and her hapless companions, whose children had populated the South American jungles with monkeys.

  But when the Panama land bridge was closed there was a massive migration from north to south of insectivores, rabbits, squirrels, mice, and later dogs, bears, weasels, and cats. The natives of South America failed to compete with these new arrivals. The extinctions took millions of years, but the empire of the marsupials was done.

  For all the difficulty and dying, this time of fast and savage changes was, perversely, a time of opportunity. In the entire four-billion-year history of the Earth there had been few times more propitious for diversification and evolutionary innovation. Amid much extinction there was wild speciation.

  And right at the center of this ecological cauldron were the children of Capo.

  The next morning dawned brightly, with a washed-out blue sky. But the air was very dry and smelled oddly sharp, and the heat was soon stifling. The animals of the savannah seemed subdued. Even the birds were quiet; the carrion eaters clung to their tree roosts like ugly black fruit.

  With their bare, sweating skin, the people were as well equipped for this hot, open dryness as any other species here. But they too began their day listlessly. They milled about their island of rock, picking at what was left of yesterday’s food.

  This wasn’t a particularly rich area. The people didn’t discuss their plans — they never did, and anyhow they had no real plans — but it was obvious they shouldn’t stay here. Before long some of the men started to set off toward the water course to continue their walk to the south.

 
; But the Brat’s condition had worsened overnight. The soles of his feet were cracked and oozing a watery pus, and when he tried to put his weight on them he cried out in pain. He wouldn’t be walking anywhere today.

  Calm, Far’s grandmother, and most of the other women stayed close to the Brat. As for the men, the women just ignored their antics as they impatiently paced up and down the trail they had begun toward the south.

  This conflict, all but wordless, over the day’s course was hurtful for them all. It was a genuine dilemma. The savannah was not like the bountiful, reliable forest of earlier times; you couldn’t just walk off in any random direction. Every day, in this sparse, changeable land, the people were faced with decisions about where to go to find food, water, what dangers to avoid. If they got it wrong, even once, the consequences were drastic. But the walkers had few children, and invested much effort in each one; you didn’t abandon one lightly.

  At last the men gave up. Some of them returned to the rock to laze in the light of the high, hot sun. A handful of others set off under Brow’s leadership on the trail of an elephant herd, one of whose infants appeared to be limping. The rest of the men — and the women and older children — dispersed to the foraging sites they had explored yesterday.

  The way these people were living — setting up a central home base, retrieving food, and sharing food and labor — was necessary. On the open plain the people had to work hard for food, and their slow-growing young extracted a high cost in care. They had to cooperate and share, one way or another. But there was no real planning. In many ways this was more like a wolf pack than any human community.

  Far spent most of the morning in the same trampled thicket her mother had worked yesterday. The ground had already been thoroughly worked over, and to find new roots and fruit required much digging. Soon she was hot, dirty, and uncomfortable. She felt restless, confined, and her long legs, folded under her in the trampled dirt and debris, seemed to ache.