Evolution

In the first years after the great split of the archaic anthropoid stock into apes and monkeys, the apes had become the Old World’s dominant primates. Though shrinking climate belts restricted them to the middle latitudes, there was plenty of room for them in a continuous band of forest that had spanned the whole of Africa and stretched across Eurasia from China to Spain. Following this green corridor the apes had walked out of Africa and spread through the Old World forests. In fact, they had migrated alongside the proboscideans.

At their peak there were more than sixty ape species. They had ranged from cat-sized to the size of a young elephant. The largest, like the giants, were leaf eaters, the midsized — those the size of Capo — took fruit, but the smallest, weighing under a kilogram or so, were insectivores, like their remote ancestors. The smaller the animal, the faster its metabolism and the higher the quality of the food it demanded. But there was room for everybody. It had been an age of apes, a mighty anthropoid empire.

Sadly for them it hadn’t lasted.

As the world continued to cool and dry, the great forest belts had shriveled into isolated islands, like this one. The vanishing of forest connections between Africa and Eurasia had isolated the Asian ape populations, which would develop independently of events in Africa, into the orangutan and its relatives. With the reduced ranges had come a dwindling of numbers. Most ape species had, in fact, already long gone extinct.

And then had come the rise of a new competitor.

Capo reached a clump of foliage where, he knew, this particular acacia had an especially productive patch of flowers. But he found the spiny branches already stripped. When he pried them aside he was met by a small, startled black face, fringed by white fur and a gray topknot. It was a monkey — like a vervet — and juice dribbled from its small mouth. It peered into Capo’s eyes, squealed, and shot out of sight before he could do anything about it.

Capo rested for a while, scratching his cheek thoughtfully.

Monkeys were a pest. Their great advantage was that they were able to eat unripe fruit. Their bodies manufactured an enzyme to neutralize the toxic chemicals used by the trees to protect their fruit until their seeds were ready to germinate. The apes could not match this. So the monkeys were able to strip the trees before the apes even arrived. They were even moving out into the grasslands, feeding off the nutlike seeds to be found there. To the apes, the monkeys were as tough a competition as the rodents had always been.

High over Capo’s head, a slim form moved, swinging gracefully and purposefully. It was a gibbon. It raced through its forest canopy at extraordinary speed. It used its body as a pendulum to gain momentum, and, like a child on a fairground swing, it pumped its legs up and down to build up its speed.

The gibbon’s body was a kind of extreme version of the apes’ long-armed, flat-chested design. The ball-and-socket joints in its shoulders and wrists had been freed up so that the gibbon could hang from its arms and twist its body through a full circle. With its low weight and extreme flexibility, the gibbon could hang from the outermost branches of the highest trees, and it was able to reach the fruits that grew at the end of the thinnest branches, safe from even tree-climbing predators. And, able to hang upside down from branches, it could reach goodies out of the grasp of other apes, who were too heavy to climb so high, and even the monkeys, who ran along the tops of the branches.

Capo peered up at the gibbon with a kind of envy for a grace, speed, and skill he could not match. But, magnificent though it was, the gibbon was not a triumph for the apes but a relic, forced by the competition it had lost to the monkeys to eke out its living on the ecological margins.

Vaguely disappointed, still hungry, Capo moved on.

At length Capo found another of his favorite resources, a stand of oil palms. The nuts of this tree had rich, oily flesh — but they were enclosed in a particularly hard outer case that rendered them immune to most animals, even the clever fingers of monkeys. But not to apes.

Capo hurled handfuls of the nuts down to the ground, then clambered down after them. He collected the nuts together, carried them to the roots of an acacia he knew, and hid them under a heap of dried palm fronds.

Then he worked his way out toward the perimeter of the forest, to where he had stashed his hammer-stones. These were cobbles that fit neatly into the palm of his hand. He selected one and headed back to his nut stash.

On his way back he passed the adolescent Howl. Briefly he considered mating her again, but Capo’s attention once a day was enough of an honor for any female.