So … along about April, single cells developed, nuclei, ribosomes, and the rest. The cells got together, algae broke oxygen free into the atmosphere, and by November the first trilobites were crawling over the sea floor. Life invaded the land around Thanksgiving. The dinosaurs appeared early in December. They perished on Christmas Day. The hominids parted company with the apes at noon today. Primitive Homo sapiens showed up maybe fifteen minutes ago. Recorded history had lasted less than one minute. And here they were, measuring the universe, ranging the Solar System, planning missions to the stars.
Where will we be by sunrise? he wondered for a dizzying moment.
It passed. The upward steepness was an illusion, he knew. To go from worm to fish took immensely longer than to go from fish to mammal because the changes were immensely greater. By comparison, an ancient insectivore was very like an ape, and an ape nearly identical with a human.
Just the same, the boy thought, we’ve become a force of nature, and not only on this world. It’s never seen anything like us before. Our little piece of extra brain tissue has got to have taken us across a threshold.
But what threshold, and what’s beyond it?
He shivered again, pushed the question away from him, and turned back to his stargazing.
II
Strictly speaking, he was mistaken. In no particular was humankind unique. Nearly all animals had language, in the sense of communication between each other; among some, parts of it were learned, not innate, and actual dialects could develop. Many were technologists, in the sense of constructing things. A few used tools, in the sense of employing foreign objects for special tasks. A very few made tools, in the sense of slightly reshaping the objects; three or four species did this with the help of something besides their own mouths or digits.
Yet none came near to humans in any of these ways. In no other lineage did language grow so rich and powerful, for in them it sprang from an unprecedented capability of abstraction and reason. They had been toolmasters par excellence since before they were fully human; fire, chipped stone, and cut wood became conditions of their further evolution. At last the scope of their technology was such that natural selection no longer had significant effect on them. Like social insects and various sea dwellers, they were so well fitted to their surroundings that they bade fair to continue unaltered for millions of years. In their case, however, they themselves created—or were—their own environment. We can, if we like, say they had crossed a threshold.
Then we must say that another, more fateful one lay ahead.
For technology was never static. It continued to develop, at an ever more furious pace. Technological evolution was radically different from biological. It was not Darwinian, driven by contingency, competition, and a blind urge to reproduce. It was Lamarckian, driven by purpose. Its units of inheritance were not genes but memes—ideas, concepts, deliberately mutated or kept intact according to foreseen needs.
Knowledge also grew, in a fashion more nearly organic and haphazard until technology made science, the systematic search for verifiable information, possible. Thereafter the two nourished one another and the pace accelerated further.
More and more it was as though technology took on a life of its own, acting independently and ruthlessly. Gunpowder brought whole societies down. The steam engine forced basic change upon whole civilizations. Its internal-combustion successor turned the planet into a single quarrelsome neighborhood, while powering an agriculture that fed billions but starved what was left of the natural world. Computers remade industry, economics, and the everyday well-nigh beyond recognition, undermined liberty, and opened a road to space. The Internet, founded as a link between military centers, spread across the globe in a matter of years, revolutionized communication and access to knowledge like nothing since movable type, curbed tyrannies, and vexed governments everywhere. Automation made traditional skills useless, raising resentment and despair side by side with new wealth and new hopes.
“Artificial intelligence” was the name given the qualities of the most advanced systems. Certain of these went into the business of enhancing artificial intelligence. Soon the business was entirely theirs.
The boy became a man. For a while he adventured on Earth, then he went into space as he had dreamed.
The machines evolved onward.
III
Long afterward—almost unimaginably long afterward—Christian Brannock recalled that day. For it had been somehow both an ending and a beginning.
He did not see this until he looked back on his life and his afterlife in fullness. At the time, he was wholly caught up in the there and then. It was not even day, except by a clock set to North American hours; and at the moment Earth was some hundred million kilometers to starward, while night still lay over Clement Base.
Morning approached, but slowly. Between sunrise and sunrise, 176 terrestrial rotations passed. Not that the men here had ever gazed directly at a sunlit landscape on Mercury. Though a darkened pane might bring the brightness down to something endurable, other radiation would strike through. Their machines above ground ranged for them. Most of these were robots, with different degrees of autonomy. One was more.
Gimmick never knew darkness. Across five hundred kilometers, Christian saw by laserlight, radarlight, amplified starlight. He felt with fingers and tendrils of metal, with sensors in the treads as the body rolled across the regolith, with subtle seismics. He tasted and smelled with flickery beams of electrons and nuclear particles. He listened electronically to whispers of radioactivity from the rock around and to the hiss and spatter of cosmic rain. Interior sensors kept him subliminally aware of balances, flows, needs, as nerves and glands did in his own body. Together, he and Gimmick made observations and decisions, like his brain alone in
