Greg Egan - The Eternal Flame

“I’m fine,” Carla managed. “Things just took me by surprise, that’s all.”

29

Carlo checked the viewfinder on the infrared recorder; the subject had moved a little off-center, but it remained in sight. Amanda had done her best to confine the lizard without alarming it, leading it with a series of treats into a twig-lined nook in its cage and then inserting a slender branch across the only easy exit. With a mound of freshly killed mites in front of it, discouraged from scampering away but not literally trapped, there was nothing compelling it to respond to the events that followed in anything but a natural manner.

“Ready?” Macaria called from the corridor.

“Ready,” Carlo replied.

Macaria dragged herself slowly into the room, three hands on two guide ropes and the fourth holding out a cage. A sufficiently timid passenger could be unsettled by any mode of transport, but Macaria was advancing as smoothly as possible, and the animal had been given a chance to grow accustomed to the process, having been moved from room to room this way every few days for the last two stints.

Carlo started his recorder. Amanda waited for Macaria to clamp the second cage onto the guide rope, less than a stride from the first, then she aimed her own recorder squarely at the new arrival before starting the paper whirring through. There was a clear line of sight between the lizards now; Carlo couldn’t swear that his subject’s single pair of darting eyes had turned far enough away from its food to take in its distant cousin, but preoccupied or not it could probably smell the other animal. In any case, the infrared channel alone might be enough: Macaria had proposed that the lizards regularly sent out faint kin-group identifiers, too weak and sporadic to show up on her images but enough to initiate a more vigorous exchange once they were detected.

They let the recorders run for six lapses, exposing as much paper as the spools could contain.

“It looked as if they barely noticed each other,” Carlo said.

“What were you expecting?” Macaria replied. “This species doesn’t show much aggression unless they’re jostling for the same scrap of food, and they’re not potential mates in any conventional sense.”

Carlo began rewinding his spool. “Doesn’t it seem strange, though? Sharing notes about the future of your offspring without even looking up from your meal?”

Amanda said, “Were people on the home world ever conscious of the fact that they were exchanging influences?”

“It’s hard to say,” Carlo admitted. “The history of the subject is so vague.”

Amanda mounted her own spool on the bench. “We might still be doing it ourselves. Even without geographical isolation, it’s not as if everyone on the Peerless mixes daily with everyone else. We can still encounter strangers.”

“Hmm.” Carlo pondered the unsettling notion that his own children might be altered somehow if Carla bumped into a reclusive herb gardener—perhaps lured from his cave by rumors of an unusually well regarded variety show.

The paper from his recorder was still blank so far, apart from the metronomic time codes along the edge; either the exchange had been over when he’d stopped the recorder, or it had never begun. Macaria’s original experiments had involved two large groups, but she’d decided to try capturing the time sequence from pairs of individuals, both for the sake of simplicity and to avoid squandering future opportunities. Once two lizards had been exposed to each other the infrared traffic between them was expected to die away, quite possibly for the rest of their lives.

“Ah, here it is!” Carlo’s tape was marked now, with a complex series of dark bands. The pattern itself did not look familiar, but the general time scale, revealed in the typical length of each feature, was comparable to that of the internal signals he’d recorded from his own body.

Amanda kept winding until she reached her lizard’s contribution. They’d made less effort to keep the second animal confined, so the bands were fainter and the pattern sometimes faded out completely.

Macaria didn’t seem to care; she just turned excitedly from spool to spool, giddy at the sheer surfeit of information. “What do they do with all this?” she wondered. “If it really does encode a set of traits, they can’t just give their offspring every trait that lands on their skin.”

Amanda said, “Maybe there’s some kind of counting going on. If a trait’s being sent out by a majority of the strangers you meet, and they seem to be in good shape, maybe that makes it worth adopting. If all these other animals have used it and thrived, why not take advantage of their experience?”

“That sounds like a great way to kill off your rivals,” Carlo suggested. “Live your own life, construct your own body one way, but send out the code for something else entirely. Gang up with your cousins so you all repeat the same lie, pretending you’re offering the newcomers the secret to good health when you’re really spreading something that will poison their children.”

“But then the code won’t spread far,” Amanda countered. “I mean, the lizards aren’t consciously planning any of this. A code that kills rivals might give some benefit to the animals who send it out, but a code for a genuinely useful trait would end up being copied far more widely.”

“The way direct inheritance selects useful traits,” Macaria said. “Only these ones spread horizontally, ignoring the family tree and leaping between branches that separated before the trait was invented.”

“So can an influence make you sick or not?” Carlo wondered. “Is that real or just folklore?” He thought for a while. “What if a code isn’t necessarily fatal, but it forces you to send out copies of itself? That would divert resources from other things your body should be doing—so it could certainly weaken you—but so long as you spewed out enough copies in a form that other people would absorb and act on, the code would spread like wildfire.”

“Maybe there are both kinds,” Amanda conceded. “Good and bad influences, just like the folk belief.”

“I always thought bad influences would turn out to be like plant blights,” Carlo admitted. “Something solid spreading through the air, not messages encoded in invisible light.”

“We haven’t actually shown that infrared signals can carry disease,” Macaria pointed out.

Amanda said, “So we should find some sick voles and see for ourselves if they’re putting out bad influences.”

“Voles?” Carlo was confused. “Why change species? We don’t know if voles use this kind of signal at all.”

“Lizards hardly ever get sick,” Macaria explained. “Or if they do, it’s impossible to tell.”

At the breeding center, Sabina was happy to oblige them. “I’ve got five families of voles in quarantine. Take your pick.”

“Can we take three?” Amanda asked. “We’ll bring them all back in a couple of bells.”

“Bring them back?” Sabina was confused. “Who’s going to want them for a second experiment?”

“We’re not going to lay a hand on them,” Macaria explained. “We just want to observe them.”

They carried three cages back to the workshop, a male and four children in each. Carlo felt sorry for the listless animals, though he’d done much worse to their relatives than disturb a convalescent’s rest.

The recordings from all three families were blank. Carlo was ready to give up, but Amanda said, “They’ve been sitting in quarantine together for days. They’ve already influenced each other. Why keep sending out the code for no reason?”

Carlo said, “What about us? We’re not worth infecting?”