changed, but she remained secure in her footing this time.
Homo sapiens shuffled from one place to another. They were all short and squat and hunched over from the effects of age or injury.
Filthy children fought playfully in the grass to the side of a rock-strewn camp. A fire burned, its smoke rising over the languid water of the river.
Her attention was attracted to guttural noises and grunts from off to the side. They were angry sounds, like two snarling animals in the moments before a fight. But when one bent over and the other stood behind, Laura realized they weren't fighting at all. It was over in moments, the male walking away and the female on all fours resuming her business without even changing position.
'Romantic, eh?' Gina said. 'I thought maybe a little sexual titillation would enliven the tour. Anyway,' she said airily, 'fire and complex languages — one million years ago.'
She raised her fingers in the air once again.
'Is that how you change the scene?' Laura asked, raising and snapping her own fingers with no effect.
'Snapping your fingers doesn't do anything,' Gina said helpfully.
'Then why do you do it?'
Gina shrugged. 'It just seems like I oughta do something.' She snapped her fingers, and the faint crackle from the walls announced their arrival at the next stop.
There were men and women lounging about, completely naked and dirty beyond belief. They looked old — their skin weather-beaten and leathery — and starving like refugees fallen to some barely survivable state under extreme conditions.
'These are the 'Joneses,'' Gina said. 'Grandpop, Grandmom, Mom, Dad, li'l Susie, and li'l Johnny. The nuclear family.'
They appeared so sick and so hungry they could barely move. They lay in or very near their excrement, and the smell was sickening.
'Are they dying?'
'Sure. So were all of their contemporaries. Dying from every imaginable ailment. Take a close look at this female, here.' Laura followed Gina over, carefully sidestepping the human waste and maggot-ridden animal carcasses. The old woman over whom Gina stood lay on her back with her eyes closed, her lips shut in a strange manner. Laura winced when she saw the sores on her face and hands.
'Grandmom, I suppose?' Laura asked with the detachment of a scientist.
'Yep.' The subject had long, stringy hair the color of dirty weeds. Her ruddy cheeks were streaked with dirt or scars, Laura couldn't tell which. She was trying to sleep despite the fact that it appeared to be midday. A large black fly buzzed at her face, and the old woman raised a hand so quickly that Laura knew she wasn't asleep, only resting. She brushed the fly away, and as she did her mouth parted. She was toothless, or should have been given the painful-looking yellow and brown stubs that were left in her mouth.
'How long ago would you guess this is, Laura?'
'Oh, I don't knew. Five hundred thousand B.C.?'
'A-a-a!' Gina said, making the sound of a game-show buzzer. 'Wrong! Ten thousand years ago. Eight thousand B.C.'
'You're kidding!' Laura said. The specimens looked like a different species.
'Nope. These are bona fide human beings. Virtually no biological evolution has occurred in the intervening ten thousand years. You take one of those children, raise him from birth in a suburban American household, and I'd give you three to two odds they'd make Bs all the way through state college.'
'Wow!' Laura said. 'That's amazing. So you're saying it's really all environment, not heredity.'
'Let's not mix our data and our conclusions. All I'm saying to you is, these creatures here are human in every respect but one. They are biologically every bit as evolved as you.' Laura stared at the horrible lot in disgust. 'Look at this one again, Laura,' Gina said, nodding toward the grandmother at their feet. 'She's going to die in six months. She has ringworm. Her body weight is dropping, and the flu will do her in this winter.' The fly crawled up the woman's nose.
The woman shook her head with a start and opened her eyes. They were blue and familiar-looking. The woman's features were… Laura's.
The woman was Laura! 'She's your age exactly — thirty-four.'
'You have no right to do that,' Laura said, turning to walk away from the disturbing sight.
'It's a simulation,' Gina said, dogging her every step. 'I'm sorry.'
'Look, what's the point?' Laura snapped, turning on Gina. 'I know the story. Aristotle, Galileo, the Renaissance. What is it that's so super-secret and enlightening that it just had to be shown to me in this workstation?'
'Those people,' Gina nodded toward the slumbering group, 'have hardware identical to yours and that of the people you know. Not that there aren't smart people and dumb people during this time and during our own. But the base level of biological evolution has not changed between this and modern time.'
'Okay. I've got it. I mean, I knew that.'
'You knew it as an academic fact. But the fact was not in your active memory. You didn't think too long or too hard about its implications.'
'Well, without visiting Gutenberg's press, why don't you just tell me what those implications are.'
'Biological evolution has ceased to be important.'
Laura looked at Gina, then shrugged. 'I've read those theories. Some of them are very interesting.'
'They're not theories, they're fact. Biological evolution has ceased to be significant because cultural evolution has exploded! It's interesting that you mentioned Gutenberg. Beginning one thousand years ago movable type sped up the flow of information and its volume of storage. Think about it! We went back a hundred million years, and the creatures were not Homo sapiens, but their brains — their information-processing hardware — were about ninety percent as capable as yours today. These Homo sapiens here' — she pointed—'are your biological equivalents. While biology inches along, culture explodes. Information levels skyrocket! Knowledge grows.'
'Okay,' Laura said, nodding her head. 'Is that it?'
'Don't you see?' Gina said. 'One hundred years ago the first practical calculating machines were invented. The computational power of those machines has risen a thousandfold every twenty years since then.' Gina grabbed Laura by the arms so that they were standing face-to-face. 'Over the next twenty years, it'll grow a millionfold. Over the twenty years after that — a billionfold.'
Gina was excited, and there was an urgency to her manner.
Laura tried to imagine what the world would be like with all that cheap computational power. She tried to conjure up images of the changes that would be wrought, which seemed of such importance to her guide.
Certainly, it would be more fundamental than better video games, higher-resolution televisions, faster computers.
It would mean that things like Gray's VR workstations would proliferate. It would mean robots like Gray's would roam the earth.
Laura looked at Gina, and the girl arched her eyebrows. 'You get it now, Laura?'
She said nothing as pictures bloomed in her head. Images of Gray's technologies turned loose on the world. Automation would raise productivity and shorten workweeks. Humans would lead lives increasingly made up more of leisure than of work.
'One more stop,' Gina said, snapping her fingers.
They stood in a world with a red sky and a purple horizon. The soil was dimly lit and rust-colored. There was a low-slung, generally rectangular metal building, not terribly different in size from a simple human house, anchored very firmly in place on all sides by long guy wires. The wires ran out to concrete anchors far to the sides of the one-story structure.
Just outside what Laura assumed to be a 'house' was a woman. She wore coveralls made of light fabric whose color Laura couldn't determine in the strange light. The woman looked toward the purple horizon. The sky in the other directions was yellowish-orange.
Gina headed toward the house, and Laura followed.
The woman up ahead wore some kind of respirator that covered only her mouth.
'Mother,' Laura heard, and a child with a gun climbed atop a rock outcropping at least a hundred meters
