Permutation City

Maria said, 'No, of course not. How stupid of me.'

Home, Maria couldn't resist logging on to the QIPS Exchange, just to find out what was going on. Operation Butterfly had vanished from the market. Omniaveritas, her knowledge miner, had picked up no news reports of a typhoon in the region; perhaps the predicted one had failed to eventuate -- or perhaps it was yet to appear, but the simulations had already given their verdict. It was strange to think that it could all be over before the storm was a reality . . . but then, by the time anything newsworthy happened, the actual meteorological data would -- hopefully -- bear no relationship at all to what would have happened if the weather control rigs had been in use. The only real-world data needed for the simulations was the common starting point, a snapshot of the planet's weather the moment before intervention would have begun.

The QIPS rate was still about fifty percent higher than normal, as ordinary users jostled to get their delayed work done. Maria hesitated; she felt like she needed cheering up, but running the Autoverse now would be stupid; it would make far more sense to wait until morning.

She logged on to the JSN, slipped on her gloves, activated the workspace. An icon of a man tripping on a banana skin, frozen in mid-fall, represented the snapshot of her interrupted task. She prodded it, and the Petri dishes reappeared in front of her instantly, the A. lamberti feeding, dividing and dying, as if the past fifteen hours had never happened.

She could have asked Aden to his face: Do you want to go to Seoul alone? Do you want a year away from me? If that's it, why don't you just say so? But he would have denied it, whether or not it was the truth. And she wouldn't have believed him, whether or not he was lying. Why ask the question, if the answer told you nothing?

And it hardly seemed to matter, now: Seoul or Sydney, welcome or not. She could reach this place from anywhere -- geographically or emotionally. She stared into the workspace, ran a gloved finger around the rim of one of the Petri dishes, and declaimed mockingly, 'My name is Maria, and I am an Autoverse addict.'

As she watched, the culture in the dish she'd touched faded from muddy blue to pure brown, and then began to turn transparent, as the viewing software ceased classifying dead A. lamberti as anything more than chance arrangements of organic molecules.

As the brown mass dissolved, though, Maria noticed something she'd missed.

A tiny speck of electric blue.

She zoomed in on it, refusing to leap to conclusions. The speck was a small cluster of surviving bacteria, growing slowly -- but that didn't prove anything. Some strains always lasted longer than others; in the most pedantic sense, there was always a degree of 'natural selection' taking place -- but the honor of being the last of the dinosaurs wasn't the kind of evolutionary triumph she was looking for.

She summoned up a histogram showing the prevalence of different forms of the epimerase enzymes, the tools she'd been pinning her hopes on to turn mutose back into nutrose . . . but there was nothing out of the ordinary, just the usual scatter of short-lived, unsuccessful mutations. No hint of how this strain was different from all of its extinct cousins.

So why was it doing so well?

Maria 'tagged' a portion of the mutose molecules in the culture medium, assigning multiple clones of Maxwell's Demon to track their movements and render them visible . . . the Autoverse equivalent of the real-world biochemist's technique of radioactive labeling -- along with something like nuclear magnetic resonance, since the demons would signal any chemical changes, as well as indicating position. She zoomed in on one surviving A. lamberti, rendered neutral gray now, and watched a swarm of phosphorescent green pin-pricks pass through the cell wall and jostle around the protoplasm in the sway of Brownian motion.

One by one, a fraction of the tags changed from green to red, marking passage through the first stage of the metabolic pathway: the attachment of an energy-rich cluster of atoms -- more or less the Autoverse equivalent of a phosphate group. But there was nothing new in that; for the first three stages of the process, the enzymes which worked with nutrose would squander energy on the impostor as if it were the real thing.

Strictly speaking, these red specks weren't mutose any more, but Maria had instructed the demons to turn an unmistakable violet, not only in the presence of nutrose itself, but also if the molecules under scrutiny were rehabilitated at a later stage -- salvaged in mid- digestion. With the epimerase enzymes unchanged, she doubted that this was happening . . . but the bacteria were thriving, somehow.

The red-tagged molecules wandered the cell at random, part-digested mixed with raw indiscriminately. Neat process diagrams of metabolism -- the real-world Embden-Meyerhof pathway, or the Autoverse's Lambert pathway -- always gave the impression of some orderly molecular conveyor belt, but the truth was, life in either system was powered by nothing at the deepest level but a sequence of chance collisions.

A few red tags turned orange. Stage two: an enzyme tightening the molecule's hexagonal ring into a pentagon, transforming the spare vertex into a protruding cluster, more exposed and reactive than before.

Still nothing new. And still no hint of violet.

Nothing further seemed to happen for so long that Maria glanced at her watch and said 'Globe,' to see if some major population center had just come on-line for the day -- but the authentic Earth-from-space view showed dawn well into the Pacific. California would have been busy since before she'd arrived home.

A few orange tags turned yellow. Stage three of the Lambert pathway, like stage one, consisted of bonding an energy-rich group of atoms to the sugar. With nutrose, there was a payoff for this, eventually, with twice as many of the molecules which supplied the energy ending up 'recharged' as had been 'drained.' Stage four, though -- the cleaving of the ring into two smaller fragments -- was the point where mutose gummed up the works irretrievably . . .

Except that one yellow speck had just split into two, before her eyes . . . and both new tags were colored violet.

Maria, startled, lost track of the evidence. Then she caught sight of the same thing happening again. And then a third time.

It took her a minute to think it through, and understand what this meant. The bacterium wasn't reversing the change she'd made to the sugar, converting mutose back into nutrose -- or doing the same to some part-digested metabolite. Instead, it must have modified the enzyme which broke the ring, coming up with a version which worked directly on the metabolite of mutose.

Maria froze the action, zoomed in, and watched a molecular-scale replay. The enzyme in question was constructed of thousands of atoms; it was impossible to spot the difference at a glance -- but there was no doubt about what it was doing. The two-atom blue-red spike she'd repositioned on the sugar was never shifted back into its 'proper' place; instead, the enzyme now accommodated the altered geometry perfectly.

She summoned up old and new versions of the enzyme, highlighted the regions where the tertiary structure was different, and probed them with her fingertips -- confirming, palpably, that the cavity in the giant molecule where the reaction took place had changed shape.

And once the ring was cleaved? The fragments were the same, whether the original sugar had been nutrose or mutose. The rest of the Lambert pathway went on as if nothing had changed.

Maria was elated, and a little dazed. People had been trying to achieve a spontaneous adaptation like this for sixteen years. She didn't even know why she'd finally succeeded; for five years she'd been tinkering with the bacterium's error correction mechanisms, trying to force A. lamberti to mutate, not more rapidly, but more randomly. Every time, she'd ended up with a strain which -- like Lambert's original, like those of other workers -- suffered the same handful of predictable, useless mutations again and again . . . almost as if something deep in the clockwork of the Autoverse itself ruled out the exuberant diversity which came so effortlessly to real-world biology. Calvin and others had suggested that, because Autoverse physics omitted the deep indeterminacy of real-world quantum mechanics -- because it lacked this vital inflow of 'true unpredictability' -- the same richness of phenomena could never be