Evolution Read online

  The primates found a place far enough from any of the predators to be able to drink unhindered. They bent and plunged their muzzles into the chill water, sucking it up gratefully.

  The largest animals of all wallowed at the muddy fringes of the lake.

  A pair of uintatheres stood side by side. These great animals looked like gargantuan rhinos, each with a set of six bony horns on its head and long upper canine teeth like a saber-toothed cat’s. Their thick hides were coated with mud, which helped keep them cool and kept off insects. They cropped placidly on the soft vegetation of the lake bottom, sucking at water stained green by algae, while a fat youngster, more agile and lively, played around his parents’ legs, barging their tree-trunk knees with a head ladened with stubby, unformed tusks. Noth watched their huge feet fearfully. Closer to the shore there walked a family of moeritherium. No more than a meter tall, the adults moved through the water with a stately calm, rumbling reassurance to each other, while their round-bodied infants splashed at their feet. They worked the lake bottom vegetation efficiently with their long noses. These were among the first proboscideans, the ancestors of elephants and mammoths. They were still more piglike than elephantine, but they were already clever and social animals.

  Around the herbivorous herds circled carnivores. These were mostly creodonts; they looked like foxes and wolverines. And there was one pack of hoofed predators — like carnivorous horses — bizarre, terrifying creatures with no analogies in human times.

  Many of these creatures looked slow and lumbering, oddly ill-formed, the results of nature’s first experiments in producing large herbivores and predators from the mammalian stock that had survived the dinosaur extinction. Open grasslands still lay millions of years in the future, along with the fleet, long-legged, graceful herbivorous forms that would adapt to their open lush spaces, and the cleverer, faster carnivores that would arise to prey on them. When that happened most of the species around Noth would succumb to extinction. But the orders that would be familiar to humans — the true primates, the hoofed animals, the rodents and bats, the deer and the horses — had already made their entrance on the stage.

  And there was no more complex and crowded an ecology anywhere on Earth right now than here on Ellesmere Island. This place was a pivot on the great migratory routes up through the Americas and over the roof of the world to Europe, Asia, and Africa. Here, pangolins from Asia, carnivores from North America, hoofed creatures from Africa, European insectivores like ancestral hedgehogs, and even anteaters from South America mingled and competed.

  Suddenly Noth pulled back his head.

  From inside the water two primates were looking out at him, a burly male and a small female. He could not smell the male, could not tell if he was kin or stranger. He screeched, baring his teeth. The male primate bared his teeth in response.

  Enraged, Noth got to his feet and displayed his musk glands to the stranger in the water — who displayed back, angering him further — and then he stamped at the water until the reflected notharctus was gone.

  Noth could recognize others of his species, could distinguish them as male or female, and as kin or not kin. But he could not recognize himself, for his mind did not contain the ability to look inward. All his life he would feel threatened by any such chance reflection.

  A sleek form burst from the water itself and came lurching up on clumsy flippered limbs onto the rocky platform. Noth and Right stumbled back. Over a snout like a crocodile’s the newcomer gazed at the two baffled primates.

  This ambulocetus was a relation of the hyena-like mesonychids. Like an otter, it was covered in sleek black fur, and it had large, powerful back legs equipped with toes ten centimeters long. Ages ago this animal’s ancestors had returned to the water, seeking a better living, and selection had begun its relentless molding. Already the ambulocetus looked more aquatic than terrestrial.

  Soon its kind would take permanently to the oceans. Its skull and neck would become shorter, and the nose migrate backward, while its ears would close so that sound would have to pass through a layer of fat. Its legs would morph at last into fins, with more bones added, the fingers and toes becoming shrunken and useless, at last disappearing. When it reached the vast spaces of the Pacific and Atlantic, it would begin to grow — ultimately becoming as large compared to its present form as a human was to a mouse — but those mighty seagoing descendants would still retain within their bodies, like fossils of bone and molecular traces, vestiges of the creatures they had once been.

  The walking whale stared uncomprehendingly at the two timid primates. Deciding this crowded shore wasn’t such a good place to bask after all, it flexed its spine and swam gracefully away.

  As the light faded, Noth and Right retreated to the shelter of the trees. But the branches were now all but bare, and cover was hard to find. They huddled in a branch’s crook.

  The herbivores splashed out of the water, family groups calling to each other. And the predators began to call, harsh doglike barks and leonine growls echoing through the sparse forest.

  As the chill settled deeper Noth felt torpor steal over him. But he felt cold, stuck here like this with only his baby sister, cold away from the huddle of his troop.

  And then, to his surprise, he was startled awake by a powerful musk scent.

  Suddenly there were notharctus all around. They were on the branches above and below him, huddled shapes with their legs drawn up beneath them and their long, fat tails dangling. Their scent told him this was his kind, but not his kin. He had not detected their scent markings before; in fact the markings were sealed in by layers of frost. But the strange notharctus had noticed him.

  Two powerful females gathered closely, drawn by the scent of an infant. One, who he thought of as Biggest, pushed aside the other — who was merely Big — to get a closer look at Right.

  Noth’s mind churned. He knew that it was vital that they be accepted by this new group. So he reached for the female closest to him, Big, and began, tentatively, to dig his fingers into the fur at the back of her legs. Big responded to his grooming, stretching out her legs with pleasure.

  But when Biggest saw what was going on she hooted and slapped them both. Noth cowered, trembling.

  Noth was bright enough to understand his own place on the social ladder — in this case, down on the bottom rung. But his social mentality had its limits. Just as he could not detect the beliefs and desires of others, so he was not smart enough to form judgments about the relative ranking of others in a group. He had got it wrong: Biggest outranked Big, and she expected this new male to pay her attention first.

  So Noth waited as Biggest played with the drowsy Right. But at least she did not drive him away. And at length Biggest let Noth approach her and groom her own dense, rank-smelling fur.

  III

  Every day was shorter than the last, every night longer. Soon there were just a few hours of bright daylight, and the intervals between the darknesses were lit only by a pink-gray twilight.

  The forest was all but silent now. Most of the birds and the large herbivore herds had long gone, migrated south to warmer, easier climes, taking their dinning cries with them. The buzzing insect swarms of high summer were a memory, leaving only larvae or deep-buried eggs, sleeping dreamlessly. The big deciduous trees had already dropped their broad leaves, which lay in a thick litter on the ground, welded together by the persistent frost. The bare trunks and leafless branches would show no signs of life until the sun returned in a few months’ time. Beneath them, plants like the ground fern had died back to their roots and rhizomes, soon to be sealed into the earth under a lid of frost and snow.

  The species here — derived from ancestral stock adapted to the balmy conditions of the tropics — had had to make ferocious adjustments to survive the extreme conditions at the pole. Every plant, wherever it lived, depended on sunlight for energy and growth, and during the endless days of summer the vegetation had lapped up the light with broad, angled leaves. But now there appro
ached a season when for months there would be no light but that of the Moon and stars, useless for growth: If the plants had kept on growing and respiring they would have burned up their energy store. So the flora were heading for a vegetable hibernation, each according to its own strategy.

  Even the plants were sleeping.

  The notharctus troop was thirty strong, and they had huddled in the branches of a big conifer. They looked like big furry fruit, their hands and feet clinging to the branches as they slept, their faces buried in their chests, their backs exposed to the cold. Frost sparkled on their new winter coats, and where a muzzle showed breath steamed, glowing blue white.

  Noth slept away the lengthening nights, his fur bristling, immersed in the body heat of the others of the troop. Sometimes he dreamed. He saw his mother fall into the jaws of the mesos. Or he was alone in an open space surrounded by hard-eyed predators. Or he was like a pup again, pushed out of a troop by adults bigger and stronger than he was, excluded by rules of which he had no innate understanding. But sometimes the dreams faded, and he fell into a kind of torpor, a blankness that prefigured the long months of hibernation to come.

  Once he woke in the night shivering, his muscles involuntarily burning energy to keep him alive.

  The sleeping world was full of light: the Moon was high and full and the forest glowed blue white and black. Long, sharp shadows striped the littered floor, and the vertical trunks of the leafless trees gave the scene an eerie geometrical precision. But the tangled branches higher up were a more complex and dismal sight, bone bare and glimmering with frost, a harsh contrast to the warm green glow of the leaves of high summer.

  In its way it was a beautiful scene, and Noth’s wide archaic eyes served him well, revealing to him detail and subtle colorations that would have been invisible to any human. But all Noth perceived was a lack: a lack of light, of warmth, of food — and a lack of kin in this group of strangers, save for his sister, whose still-growing body was buried somewhere in the huddling troop. And he knew on a deep cellular level that the true winter had yet to begin, long, drawn-out months of a kind of slow agony as his body consumed itself in order to keep him alive.

  He squirmed across the branch, trying to force his way deeper into the group. Each of the adults knew that it was in everybody’s long-term interests that she should take her turn at the edge of the group, briefly suffering the cold in order to shelter the rest; it wouldn’t help to have outliers die of frostbite. But still Noth’s lowly rank worked against him, and when the other males picked up his scent they sleepily combined to push him back out of the huddle, so he finished up almost as exposed as when he had started.

  He lifted his muzzle and puffed out a breath, hooting mournfully.

  These primates could draw no comfort from those around them. Noth found pleasure in grooming — but only in his own physical sensations, and in the effect it had on others’ behavior toward him, not in how others felt. The other notharctus were simply a part of his environment, like the conifer trees and podocarps, the foragers and predators and prey: nothing to do with him.

  These huddling notharctus, despite their physical closeness, were each lonelier than any human would ever be. Noth was forever locked inside the prison of his head, forced to endure his miseries and fears alone.

  The morning dawned clear, but a freezing mist lay over the forest. Even though the sun grew bright there was little heat to be had from its rays.

  The notharctus stretched limbs stiff with cold and long hours of immobility. Cautiously, watchfully, they headed down to the ground. On the forest floor they scattered slowly. The senior females moved around the edge of this loose clearing, using their wrists, armpits, and genitals to renew scent markers.

  Noth picked through the frozen mulch. The dead leaves were of no use to him, but he had learned to burrow under places where the leaf litter was particularly thick. The mulching leaves could trap moisture and keep the frost away; here there was dew to lap up, and unfrozen ground to dig in search of tubers, roots, or even the rhizomes of hardy ferns.

  A series of hooting cries broke out, startlingly loud, echoing through the forest. Noth looked up, whiskers twitching.

  There was a commotion around a stand of podocarp. Noth saw that a group of notharctus, strange females with a scattering of pups, had come out of the forest. They were approaching the podocarp.

  Biggest and some of the other females dashed forward. The troop’s big dominant male — who Noth thought of as something like the Emperor — joined in the females’ charge. Soon they were all displaying ferociously, hooting and scraping musk over their long tails. The strange females cowered back, but they responded in kind. The forest briefly filled up with the cacophony of the argument.

  The female clans, the heart of the notharctus’ society, were fiercely territorial. These strange females had ignored the scent markers left by Big and the others, bright warning signs in a notharctus’ sensorium. At this time of year food was becoming short; in the final scramble to stoke up their bodies’ stores for the rigors of winter, a rich stand of podocarp was worth fighting for.

  The females, with babies clinging to their fur, went further in their wars than their males were prepared to. They quickly escalated the confrontation to lunges and feints and even slashes with canine teeth. The females fought like knife fighters.

  But it wasn’t going to work. Though not one notharctus laid a paw on another, the display by Biggest and the rest overwhelmed the newcomers. They backed off toward the long gray-brown shadows of the deeper forest — though not before one older pup had lunged forward, cheekily sunk his teeth into a cold-wizened fruit, and run off with his bounty before he could be stopped.

  Suddenly aware of the vulnerability of their treasure, the females closed around the podocarp now, munching greedily at the fruit. Some of the older, more powerful males, including the Emperor, were soon feeding alongside Biggest and the rest. Noth, with the other young males, circled the feeding group, waiting his turn at whatever would be left.

  He dared not challenge the Emperor.

  Male notharctus had their own complex and different social structure, overlaying that of the females. And it was all about mating, which was the most important thing — the only thing. The Emperor had a large territory, including the ranges of many female groups. He would aim to mate with all the females in his territory, and so maximize his chances of propagating his genes. He would scent mark females to repel other suitors. And he would fight fiercely to keep other strong males away from his wide empire, just as Noth’s father had fought to exclude Solo.

  The Emperor had done well to hold on to his wide-ranging fiefdom for more than two years. But like all of his short-lived kind, he was aging quickly. Even Noth, the lowliest newcomer, made endless automatic computations of the Emperor’s strength and fitness; the drive to mate, to produce offspring, to see his own line go on, was as strong in Noth as in any of the males here. Soon the Emperor would surely meet a challenge he could not withstand.

  But for now, Noth was in no position to challenge the Emperor or any of the stronger males in the loose pecking order above him. And he could see that the supply of podocarp fruit was dwindling rapidly.

  With a frustrated hoot he hurried over the forest floor and scampered briskly into a tree. The branches, slippery with residual frost, dew, and lichen, were all but bare of leaves and fruit. But it might still be possible to find caches of nuts or seeds, stashed away by providential forest creatures.

  He came to a hollow in an aging tree trunk. In its dank, rotting interior, he saw the gleam of nutshells. He reached in with his small, agile hands and hauled out one of the nuts. The shell was round, seamless, complete. When he rattled it he could hear the kernel inside, and saliva spurted into his mouth. But when he bit into the shell his teeth slid over the smooth, hard surface. Irritated, he tried again.

  There was an almighty hissing. He hooted, dropped the nut, and scuttled to a higher branch.

  A creature th
e size of a large domestic cat came scrambling clumsily toward the nut cache. It raised its head to Noth and hissed again, showing a pink mouth with powerful upper and lower incisors. Satisfied that it had driven off the raider, it dug out one of its stored nuts and, with a clench of its powerful jaws, cracked the shell. Soon it was nibbling purposefully, widening the hole it had made. At last it reached the nut’s kernel — Noth, tucked behind the tree trunk, was almost overwhelmed by the sudden sweet aroma — and fed noisily.

  This ailuravus looked something like a rudimentary squirrel, with a mouselike face. It had a long bushy tail, the purpose of which was to slow its fall, parachute-like, every time it tumbled out of a tree, as it frequently did. Although it was clumsier than the notharctus as it moved about in the trees, lacking a primate’s grasping hands and feet, it was more than big enough to have fought off Noth.

  The ailuravus was one of the first rodents. That vast, enduring family had emerged a few million years earlier in Asia, and had since migrated around the world. This small encounter was a skirmish at the start of an epochal conflict for resources between the primates and the rodents.

  And the rodents were already winning.

  They were beating primates to the food, for one thing. Noth would have needed a nutcracker to eat hazelnuts or brazil nuts, and a millstone to process grains like wheat and barley. But the rodents, with their ferocious, ever-growing incisors, could break through the toughest nut and grain seed coats. Soon they would begin to consume the fruits of the best trees before they were even ripe.

  Not only that, the rodents outbred the primates by a large factor. This ailu could produce several litters within a single year. Many of its young would fall to starvation, competition with their siblings, or predation by birds and carnivores. But it was enough that some should survive to continue the line, and for the ailu each of its young represented little investment — unlike the notharctus who bred just once a year and for whom the loss of a single pup was a significant disaster. And the rodents’ vast litters incidentally offered up much raw material to the blind sculptors of natural selection; their evolutionary rate was ferocious.