Evolution

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 the 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.