Evolution

At last they got the logs into the water. They floated, tied together to make a stable surface.

Ko-Ko and Hands threw themselves forward, splashing heavily. They both lay flat on the logs, legs stretched behind them, and began to paddle. Slowly they pulled away from the shore. But the waves tipped the logs up and down — and eventually over, pitching both men into the water. And then the logs’ bindings came loose.

Hands came staggering back, spluttering and growling. With Ko-Ko, he hauled the logs back out of the water onto the beach.

Pebble knew that there had been no danger, for the water here was shallow enough to walk out to shore. But further away it deepened quickly — and that was where they must travel, if they were to reach the island.

So they kept working, trying different combinations, over and over.

Much had changed in Pebble’s life in seven years.

Gradually those who had come with him from Flatnose’s village faded out of the world. Hyena had never recovered from his stab wound, and they had put him in the ground. And not long after that they had had to put Dust in the ground too. Gradually Pebble’s mother had seemed to have grown fond of Harpoon, this peculiar stranger who lay with her son. But at last her growing frailty overcame her strength of will.

But where life was lost, so new life was created. His two children were close in age — six and seven years old — but they were quite different.

Sunset was the younger, at six. The boy was the result of Pebble’s reluctant union with Cry, who had continued to pursue him long after he had formed his bond with Harpoon. Sunset was squat, round, a ball of energy and muscle, and above a thick, shadowing browridge his hair was still the startling red it had been when he was born, Ice-Age-sunset red.

Sunset had brought poor Cry no pleasure, though. She had died in giving him birth, to the end protesting about the presence of the new people among them.

Pebble’s other child, Smooth, had come from Harpoon. Though she had something of her father’s chunkiness, she was much more like her mother’s kind. Already she was taller than Sunset. Every time he saw her, Pebble was struck by Smooth’s flat face, and the ridgeless brow that swept up above her clear eyes.

Pebble had had no reason to be surprised when his sexual contact with Harpoon had resulted in a child. Now, in fact, she was pregnant again. The changes between the ancestral stock and Harpoon’s generation, though they were so striking, were not yet so fundamental that the two kinds of people could not crossbreed — and indeed their hybrid children would not be mules. They would be fertile.

Thus Harpoon’s modified genes, and her new body plan and way of life, had begun to propagate through the wider population of robust folk. Thus the thread of genetic destiny would pass on through Smooth, child of human-form and robust, into the future.

As the long afternoon wore on, driven by Pebble’s determination, they kept on trying to make the logs work.

It was frustrating. They had no way of discussing their ideas. Their language was too simple for that. And even the new folk were not particularly inventive with technology, for the compartment walls in their highly specialized minds denied them full awareness of what they were doing. They weren’t able to think it through. It was something like trying to learn a new body skill, like riding a bicycle; conscious effort didn’t help. And besides the work was uncoordinated, and only progressed when somebody was passionate enough to bully the rest.

But at last, quite suddenly, Ko-Ko hit on a solution. He splashed into the water. "Ya, ya!" With frantic yells and blows, he forced the swimmers to hold on to a single log and let it float. Then he went to the far end and, swimming strongly himself, guided the log out through the choppy inshore waves to the calmer waters beyond.

Pebble watched, amazed. It worked. Rather than riding the log, they used it as a float to help these nonswimmers swim. Soon the log was so far from the shore that all he could see was a row of bobbing heads and the black stripe of the log between them.

By clinging to the log and paddling for all they were worth even the robusts, too heavy to swim, were able to cross the water, far out of their depth. It was obvious to everybody that at last they had found a way to cross the strait that had baffled Pebble for years.

Pebble hollered his triumph. His sons ran to him. He picked up Smooth and whirled her, squealing, through the sunlit air, while Sunset pulled at his legs, clamoring for attention.

The raiding party landed on a little crescent of shell-strewn sand that nestled beneath walls of eroded blue-black rock. They staggered out of the water and lay gasping on the beach. Pebble saw immediately that everybody, robust and skinny alike, had made it to the shore.