Evolution

by Stephen Baxter

  But at last Antarctica had settled over the southern pole, and the great ice cap had slowly grown.

  The days grew short, the crimson sun arcing only briefly over the horizon. The ground hardened with frost. Many plant species died back to ground level, their spores waiting out the return of the summer’s brief warmth.

  There was little fresh snow. In fact, much of the continent was technically a semidesert: What snow did fall came as hard crystalline flakes that rested on the ground like rock until the wind gathered it into banks and drifts.

  But the snow, sparse as it was, was essential for the burrowers.

  Those who had survived the summer and autumn began to dig into the snow drifts, constructing intricate tunnel systems beneath the hard-crusted upper layers. The tunnels were elaborate, humid, nivean cities, the walls hardened by the passage of many small, warm bodies, the air filled with a warm, damp-fur smell. The burrows were not exactly warm inside, but the temperature never dropped below freezing.

  Outside, auroras flapped silently across the star-stained winter sky.

  The leaellyn who had stolen the eggs from Dig was one of a pack, mostly siblings, who had hunted together in a small group centered on one dominant breeding pair. In the winter, as they felt their customary cold-weather torpor come on, the leaellyn pack huddled together.

  The leaellyns were descended from small, agile herbivorous dinosaurs that had once swarmed in great nervous clans over the floor of the Antarctic forest. In those days the leaellyns could grow as large as an adult human, and they had big eyes well adapted to the darkness of the polar forests. But with the great chill the leaellyns had become dwarfed, fatter, and covered with scaly feathers for insulation.

  And, as the megayears had worn away, they had learned to eat meat.

  As the cold deepened, the pack members slid into unconsciousness. Their metabolisms slowed to a crawl, astonishingly slow, just enough to keep their flesh from freezing. It was an ancient strategy, shaped by millions of years of habitation in these polar regions, and it had always proven effective.

  But not this time. For there had never been a winter as cold as this. In the worst of it the leaellyn group was overwhelmed by a storm. The savage wind took away too much of their body heat. Ice formed inside the leaellyns’ flesh, shattering the structure of their cells; gradually the frostbite extended cold daggers deep into their small bodies.

  But the leaellyns felt no pain. Their slumber was a silent, dreamless, reptilian sleep, deeper than any mammal would ever know, and it segued smoothly into death.

  Every year the summers were shorter, the onset of winter harder. Each spring the great ice cap that lay over the center of the continent, a place where nothing could live, advanced a little further. Once there had been tall trees here: conifers, tree ferns, and the ancient podocarps, with clusters of heavy fruit at their bases. It had been a forest where Noth would have been at home. But now those trees existed only as seams of coal buried deep beneath Dig’s feet, long since felled by the cold. It had been many millions of years since any of Dig’s ancestors had climbed off the ground.

  The primates of Antarctica had had to become adapted to the cold. They could not grow larger; competition with the dinosaurs saw to that. But they developed layers of insulation, fat and fur, designed to trap their body heat. Dig’s feet were kept so cold there was little temperature difference between them and the ground, and little heat was lost. Cold blood coming up into her torso from her feet was pushed through blood vessels containing warm blood that ran the other way. So the descending blood was cooled before it ever got to her feet. The fat in her legs and feet was a special kind, made of shorter hydrocarbon chains, with a low melting point. Otherwise it would have hardened, like chilled butter. And so on.

  For all her cold adaptations Dig was still a primate. She still retained the agile hands and strong forearms of her ancestry. And, though her brain was much diminished from her ancestors’ — in this straitened environment a big brain was an expensive luxury, and animals were no smarter than they needed to be — she was smarter than any lemming.

  But the climate was getting colder yet. And every year the remnant animals and plants were crowded into an increasingly narrow strip of tundra close to the coast.

  The endgame was approaching.

  Dig found herself laboring for breath.

  In a sudden panic, she scrabbled at the snow above her, hands evolved for climbing trees now digging their way through a roof of snow.

  She pushed her way out of the burrow and into a thin spring light, shockingly bright. A gush of fetid air followed her, steaming in the cold — fetid, and laden with the stink of death.

  She was a bony bundle of urine-stained skin and fur on a vast, virgin snowscape. The sun was high enough above the horizon to hang like a yellow lantern in a purple-blue sky. Spring was advanced, then. But nothing moved: no birds, no raptors, no dwarf allo chicks erupting from their wintry caves. No other burrower emerged onto the snow; not one of her own kin followed her.

  She began to work her way down the bank of snow. She moved stiffly, her joints painful, a ravening hunger in her belly, a thirst in her throat. The long hibernation had used up about a quarter of her body mass. And she was shivering.

  Shivering was a great failure of her body’s cold-resistant systems, a last-resort option to generate body heat with muscular movement that burned up huge amounts of energy. Shivering shouldn’t be happening.

  Something was wrong.

  She reached the bare ground that fringed the sea. The soil was icebound, still as hard as a rock. And despite the lateness of the season nothing grew here, not yet; spores and seeds still lay dormant in the ground.

  She came across a group of leaellynasaurs. In the cold, they had intertwined their limbs and necks until they had formed a kind of interlocked, feathery sculpture. Instinctively she flattened herself against the snow.

  But the leaellyns were no threat. They were dead, locked in their final embrace. If Dig had pushed, the assemblage might have toppled over, frozen feathers breaking off like icicles.

  She hurried on, leaving the leaellyns to their final sleep.

  She reached a little headland that overlooked the ocean. She had stood in this place at the end of last summer, under a small stand of fern, watching raptor and frog battle. Now, even the fern’s spores were locked inside the bare ground, and there was nothing to eat. Before her the sea was a plain of unbroken white, all the way to the horizon. She quailed before the lifeless geometry: a horizon sharp as a blade, flat white below, empty blue dome above.

  Only at the shore was there a break from the monotony. Here the sea’s relentless swell had broken the ice, and here, even now, life swarmed. Dig could see tiny crustaceans thrusting through the surface waters, gorging themselves on plankton. And jellyfish, small and large, pulsed through this havoc, all but translucent, lacy, delicate creatures that rode the swell of the water.

  Even here, at the extremes of the Earth, the endless sea teemed with life, as it always had. But there was nothing for Dig.

  As the great global cooling downturn continued, so the great clamp of the ice tightened with each passing year. The unique assemblage of animals and plants, trapped on this immense, isolated raft, had nowhere to go. And in the end, evolution could offer no defense against the ice’s final victory.

  It was a gruesome extinction event, hidden from the rest of the planet, drawn out over millions of years. An entire biota was being frozen to death. When the animals and plants were all gone, the monstrous ice sheet that sat squat over the continent’s heart would extend further, sending glaciers to grind their way through the rock until the ice’s lifeless abstraction met the sea itself. And though the deeper fossils and coal beds of ancient times would survive, there would be no trace left to say that Dig’s world of tundra, and the unique life that had inhabited it, had ever existed.

  Dispirited, she turned away and set off over the frozen ground, seeking food.

  CH
APTER 8

  Fragments

  North African coast. Circa 5 million years before present.

  I

  As light leaked into the sky, Capo woke. Lying in his treetop nest he yawned, his lips spreading wide to expose his thick gums, and he stretched his long, furry limbs. Then he cupped his balls in one hand and scratched them comfortably.

  Capo looked something like a chimpanzee, but there were not yet any chimps in the world. He was an ape, though. In the long years since the death of Roamer, the burgeoning families of primates had diverged, and Capo’s line had split off from the monkeys some twenty million years ago. And yet — still some five million years before the rise of true humans — the great age of the apes had already come and gone.

  Capo squinted into the sky. The sky was gray blue and free of clouds. It would be another long, hot, sunny day.

  And a good day. He rubbed his penis thoughtfully. His morning erection felt tight, as it always did. Some of the most troublesome of the subordinate males had sloped off into the deeper forest a few days ago. It ought to be weeks before they were back, weeks of relative calm and order. Easy work for Capo.

  In the stillness of morning, sound carried far. Lying here, his thoughts rambling, Capo could hear a distant roaring, like the endless grumble of some vast, wounded beast. It came roughly from the west. He listened for a few heartbeats, and his hairs prickled at the sullen majesty of the never-ending, baffling rumble; it was a sound of awesome power. But there was never anything there, nothing to see. It had been there in the background all his life, unchanging, incomprehensible — and remote enough not to matter.

  He felt a nagging unease, but not about the noise. A vague concern crept up on him in such reflective moments.

  Capo was more than forty years old. His body bore the scars of many battles and the patchy baldness of endless grooming. He was old enough and smart enough to remember many seasons — not as a linear narrative but in glimpses, shards, like vivid scenes cut out of a movie and jumbled up. And on a deep level he knew that the world was not as it had been in the past. Things were changing, and not necessarily for the better.

  But there was nothing to be done about it.

  Languorously he rolled over onto his belly. His nest was just a mass of thin branches folded over and kept in place by his weight. Through its loose structure he could make out the troop scattered through the tree’s foliage, primates roosting like birds. With a soft grunt he let his bladder go. The piss sprayed messily from his penis, still half erect, and rained down into the tree.

  It splashed Leaf, one of the senior females, who had been asleep on her back with her infant clutching her belly fur. She woke with a start, wiping thick urine from her eyes, and hooted her protest.

  His time of reflection over, the last of his erection shriveling, Capo sat up and vaulted out of his nest.

  Time to go to work. A great black-brown ball of fur, he proceeded to crash through the tree. He smashed nests, punched and kicked their occupants, and screeched and leapt. He kept this up until the whole tree was a leafy bedlam, and there was no possibility of anybody staying asleep, or not being aware of Capo’s dominant presence.

  He made one very satisfactory hard landing right in the middle of the nest of Finger, a stocky younger male with a very agile brain and hands. Finger curled up, chattering, and tried to lift his backside in a gesture of submission. But Capo targeted the backside with one well-aimed kick, and Finger, shrieking, went tumbling down through the foliage toward the ground. It was high time Finger was taught a lesson; he had been getting too cocky for Capo’s liking.

  At length Capo reached the ground, fur bristling, panting hard. He was on the edge of a small clearing centered on a clogged, marshy pond. He still wasn’t done with his display. He threw himself back and forth around the line of trees, drumming with open palms on tree trunks, ripping off thin branches and shaking them so their leaves cascaded around him, screeching and hooting the while.

  Finger had picked himself up from where he had plummeted. Limping slightly, he crawled into the shade of a low palm and cowered away from his master’s display. Other males hopped and hooted in backside-kissing support. One or two females were already up. They kept out of Capo’s way, but otherwise maintained their own morning routines.

  As he finished his display, Capo spotted Howl, a female with a peculiarly high-pitched way of calling. She was crouching at the base of an acacia, picking lumps off a morel and popping them into her mouth. Howl was not yet pubescent, but she wasn’t far off. Spying the tight pucker of her genitals, Capo immediately hardened.

  Still bristling, panting a little, he swaggered over to Howl, lifted her hips, and smoothly entered her. Her passage was pleasingly tight, and Capo’s supporters hooted and growled, drumming on the ground, urging on their hero. Howl did not resist, adjusting her posture to accommodate him. But as he thrust, she continued to pluck bits of morel, not much interested.

  Capo withdrew from Howl before he ejaculated: too early in the day for that. But as a coup de grâce he turned his back on his cowering subordinates, bent over, and ejected a spray of shit that showered over them. Then he threw himself flat on the grass, arms akimbo, and allowed a few of his more favored subordinates to come close and begin the day’s grooming.

  Thus the great boss, the capo di capo of this troop — the progenitor of mankind, the ancestor of Socrates and Newton and Napoleon — had begun his day in suitable splendor.

  The next priority was to fill his belly.

  Capo selected one of his subordinates — Frond, a tall, sinewy, nervous creature — and, hooting loudly, delivered a series of slaps and blows to the cowering creature’s head.

  Frond quickly got the message. His assignment was to lead the troop’s daily forage in search of food and water. He selected a direction — east, as it happened, into the light of the rising sun — and, his gait a mixture of clumsy knuckle-walking and upright sprinting, he ran back and forth along a trail that led that way, glancing back at Capo for approval.

  Capo had no reason not to choose that direction. With a swagger, his big knuckles punching into the soft ground, he set out after Frond. The rest of the troop quickly formed up behind him, males and females alike, infants clinging to their mothers’ bellies.

  The troop worked its way through the trees at the forest fringe, foraging systematically, after their fashion. Mostly they sought fruit, though they were prepared to take insects and even meat if it was available. The males noisily postured and competed, but the females moved more calmly. The smallest infants stayed with their mothers, though older youngsters rolled and wrestled.

  As they worked their endless way through the forest, the friendships of the females quietly endured. The truth of Capo’s society was that the females were its foundation. The females stuck to their kinship groups and shared the food they found — a practice that made good genetic sense, as your aunt and nieces and sisters shared your own heritage. As for the males, they just went where the females went, their dominance battles a kind of showy superstructure, signifying very little of true importance for the troop.

  With a moist dick and pleasantly aching fists, and the prospect of a belly soon to be filled, Capo ought to have been as happy as he could be. Life was good, here in the forest. For Capo, top of the heap, it could hardly get any better. But still that bit of unease lingered.

  Unfortunately for Capo’s mood, the pickings that morning were poor. They were forced to keep moving.

  They came across other animals, here in the forest. There were okapi — short-necked giraffes — and pygmy hippos and dwarf forest proboscideans. It was an ancient fauna clinging to the conservatism of forest ways. And there were other primates too. They passed a pair of giants: huge, broad-shouldered, silver-haired creatures who sat massively on the ground, feeding on the leaves they plucked from the trees.

  They were like the potbellies of Roamer’s day. Capo’s forebears had developed a new kind of teeth, the better to cope with
their fruit diet: Capo had large incisors for biting, necessary for fruit, whereas his molars were small. These leaf eaters’ teeth were the other way around; leaves didn’t need much biting but took a lot of chewing. Closely related to the gigantopithecines of Asia, these great beasts, weighing a quarter of a ton each, were among the largest primates who would ever live. But the giants were rare in Africa now.

  They were not in direct competition with Capo’s troop, who, lacking the giants’ immense multiple fermenting stomachs, could not feed on leaves. Still, it bothered Capo to have to divert his course to avoid these silent, patient, statuesque creatures. Not wishing to lose face, Capo knuckle-walked up to the larger of the giants — a male — and displayed, fur bristling, running in circles, drumming on the ground. The leaf eater watched, impassive and incurious. Even sitting down he towered over Capo.

  Honor satisfied, Capo skirted the giants and moved on.

  It wasn’t long before the morning march came to an end, as the troop ran out of trees.

  Here was the root of Capo’s unease. This shrinking, half-flooded patch of forest was not as abundant a home as it used to be. It was just an island, in fact, in a greater, more open world.

  Peering out of the trees, he glimpsed that world, still emerging from a misty dawn.

  This scrap of forest lay in the palm of an extensive, glimmering plain. The land was like a park, a mix of open green plains and patches of forest. Much of the forest was palms and acacias, but there was some mixed woodland, both conifers and deciduous trees — walnut, oak, elm, birch, juniper.

  What would most have surprised Roamer, Capo’s distant great-aunt, was the nature of the ground cover that stretched over those open green areas. It was grass: hardy, resistant, now spreading with slow, unheralded triumph across the world.