by Greg Egan
Prabir complied. Tiny black ants were swarming over the motionless creature, which was more pink now than black. It was already half eaten.
‘Did that look like carrion to you when it hit the ground?’
‘Hardly.’ Prabir reached down gingerly; he didn’t particularly want to fight the ants for their meal, but it would be too much hard work to give up and go looking for another specimen every time something like this happened.
‘Be careful,’ Grant advised him redundantly.
He grabbed one bedraggled wing between thumb and forefinger and tried shaking the carcass clean. Ants swarmed on to his hand immediately; he dropped the dead bird and started swatting them. He crushed most of them in a matter of seconds, but the survivors continued doing something extremely painful – stinging or biting, they were too small for him to tell.
Grant fished out the repellent and sprayed his hand; they’d never thought before to be so thorough. The solvent itself smarted; his skin was broken in a hundred places.
‘Are you OK?’
‘Yeah, yeah.’ His hand was throbbing, but if he’d been stung he didn’t seem to be suffering any systemic reaction.
Grant sprayed her own right hand, and the carcass, then broke a branch off a shrub and used it as a hook. There wasn’t much flesh left on the bird, but it would be more than enough for DNA analysis.
‘At least they weren’t army ants,’ she joked. ‘We’d be lucky to have salvaged anything.’
Prabir eyed the ground nervously. ‘No, but I didn’t think we were in Guatemala.’ His old implant might have given him a rose-coloured view of Teranesia’s insects, but he was sure there’d been nothing as aggressive as this.
He said, ‘If this whole thing is a response to genetic damage, wouldn’t it have shown up in some experiment by now? They’ve been irradiating fruit flies for a hundred years, at every conceivable dosage.’
Grant was way ahead of him. ‘Maybe it has shown up. But one or two individual recovered traits wouldn’t necessarily stand out clearly from genuinely fortuitous mutations. It’s not as if the entire organism would regress to an archaic form that any competent palaeo-entomologist would recognise instantly. I think what’s happening with the displaced organs in some of the mutants is that part of the embryology has been modified out of step with the rest; the result isn’t harmful, because there’s so much conserved across the gap, but it leads to some detailed anatomy that’s neither modern nor archaic.’
‘Right.’ Prabir still couldn’t see how the cockatoo’s teeth had come to be placed so efficiently, but he didn’t know enough about the subject to argue the point with any confidence. ‘But when you look at the original DNA of the pigeons that used to live on Bandanaira, can you see where the recovered traits have come from? Can you pin down the sequences that have been cleaned up and switched on in the birds we saw?’
Grant shook her head. ‘But I don’t expect to be able to do that until I understand how the repair process works. The original sequence might be cut out and spliced into a new location, and even hunting through the whole genome for partial matches wouldn’t necessarily find it.’
Prabir thought this over. ‘So what you really need to do is catch it in the act? Instead of just seeing the “before” and “after” genomes, if we could find an animal where the process was still going on—’
‘Ideally, yes,’ Grant agreed. ‘Though I don’t know how we’d recognise it. I don’t know what we’d look for.’
Nor did he. But it might still be happening most often, and most visibly, on the island where it had happened first.
Any lingering fear of retribution from Grant was absurd; they were friends now, weren’t they? And however annoyed she might be that he’d lied to her, she was hardly going to abandon him here.
But Madhusree had promised to say nothing. How would she feel if he broke the silence first, without consulting her? And if Grant scooped the expedition with his help, the discovery wouldn’t become public knowledge, it would be the property of her sponsor.
He said, ‘So all we can do is gather as many samples as we can, and hope to get lucky?’
Grant squared her shoulders stoically. ‘That’s right. When you don’t know what you’re looking for, there’s no substitute for overkill.’
They stayed on the island for six days. Prabir didn’t exactly grow inured to the drudgery, but there was some consolation in being so tired every night that he could fall asleep the moment he was horizontal. They found twenty-three species of animals and plants that appeared to be novel, though Grant pointed out that the odds were good that one or two had simply failed to make it into the taxonomic databases.
The second island was another half-day’s sailing away. Within an hour of coming ashore, they’d seen what appeared to be the same thorny shrubs, the same flies, the same vicious ants.
They worked their way deeper into the jungle, staying within sight of each other but collecting samples independently. Prabir had rigged up software that took images from his notepad’s camera and searched the major databases for a visual match to any previously described species. Grant scorned this approach; she had no encyclopaedic knowledge of the region’s original wildlife, but she seemed to have acquired the knack of recognising subtle clues in body plan and coloration. At the end of the day, judged against the sequencing results, their hit rates had turned out to be virtually identical.
Prabir stopped beside a white orchid, a single bell-shaped flower almost half a metre wide. Its thick green stem wound around a tree trunk and ended in a skein of white roots that clung to the bark, wreathed in fungus but otherwise naked to the air. There was an insect sitting in the maw of the flower, a beetle with iridescent green wings. He crouched down for a closer look; he was almost certain that this was a species Grant had found on the previous island that had turned out to be modified. If so, it was worth taking for comparison.
He sprayed the beetle with insecticide and waited a few seconds. There was no death dance, none of the usual convulsions. He gripped it by the sides and tried to dislodge it, but it seemed to be anchored to the petal.
The flower began to close, the petals sliding smoothly together. Prabir drew his hand back, but the flower came with it; the sticky secretion that had trapped the beetle had also glued his fingers to its carapace. He laughed. ‘Feed me! Feed me!’ He grabbed hold of the stem of the orchid and tried to extricate himself by yanking his hands apart, but he wasn’t strong enough to break the adhesion, or tear the plant. It was like being superglued to a heavy-duty rope wound around the tree trunk.
The flower now loosely enclosed his forearm, and the reflex action hadn’t stopped. He tried to stay calm: pitcher plants and sundews took days or weeks to digest a few flies; he wasn’t likely to get doused in anything that would strip his flesh to the bone. He fumbled for his pocket knife and attacked the petal. It was tough and fibrous as a palm leaf, but once he’d punctured it he managed to saw through it easily enough, hacking out a piece around the beetle. The orchid began to unfurl immediately, maybe because he’d taken away the source of the attachment signal. But why hadn’t it closed on the beetle itself?
Grant must have seen him struggling; she approached with a look of concern that turned into an enquiring smile as she realised that he was uninjured.
Using the knife blade, he managed to lever one finger free of the beetle. Grant took his hand and peered at what was still glued to his thumb. ‘That’s extraordinary.’
‘Do you mind?’ Prabir pulled his hand back. ‘If you want to wait five seconds, you can have a proper look.’ He forced the tip of the blade between skin and carapace, and finally dislodged the beetle, with orchid fragment attached.
Grant picked it up and examined it. ‘I was right. It’s a lure.’
‘You’re joking.’ Prabir took it from her and held it up to the light, examining the petal edge-on. What he’d taken for an insect was an elaborately coloured nodule growing out of the plant itself. He said, ‘So a beetl
e comes along and tries to mate with this?’
‘A beetle to mate with it, or maybe something else that thinks it’s going to eat the “beetle”. It’s quite common for orchids to have one entire petal that looks like a female wasp or bee, as a pollination lure. But with an adhesive like that, I have a feeling the end result wouldn’t be a light dusting with pollen.’
Prabir re-examined the damaged orchid. There was no pool of digestive juices waiting at the bottom of the flower, but perhaps it would have secreted something if it had been able to close fully.
He passed the lure back to Grant. ‘Don’t you think it looks like that modified species you found a few days ago?’
‘Dark-green shiny wing cases, about two centimetres long? Do you know how many beetles would fit that description?’
‘I think it looks identical.’ Prabir waited for her to contradict him, but she remained silent. ‘If it is, isn’t that stretching coincidence? For a process that wakens old genes in this orchid to synchronise so perfectly with the same process in the beetle—’
Grant said defensively, ‘They might have been here together for millions of years. It’s not inconceivable that two independently recovered traits could reveal an archaic act of mimicry.’
‘But I thought the beetle wouldn’t look exactly like any of its ancestors. I thought you said the mixed embryology produced distorted body plans.’
‘The lure could be distorted too.’
‘Sure. But in the same way? When its morphogenesis is completely different?’
Grant regarded him irritably. ‘I really don’t think they look that similar.’
They’d been photographing everything; they didn’t need to wait until they were back on the boat to make a comparison. Prabir summoned up the image and offered her his notepad.
After almost a minute Grant conceded, ‘You’re right. They’re very close.’ She looked up from the screen. ‘I can’t explain that.’
Prabir nodded soberly. ‘Don’t worry; you’ll figure it out. Your hypothesis is still the only one I’ve heard that makes the slightest sense.’
Grant said drily, ‘You mean compared to Paul Sutton’s highly esteemed theory of Divine Cosmic Ecotropy?’
‘I didn’t mean it that way. The last I heard from Madhusree, all her university colleagues were completely stumped, so you still have the advantage on them.’
Grant gave him a weary smile. ‘Thanks for the vote of confidence. But remember how long it took me to confess to the idea. Do you really expect that these people would have been any more forthcoming with your sister?’
The third island was the largest of the six Grant had chosen, almost three kilometres across. Two weeks before, that had sounded like nothing to Prabir’s urbanised ear; he’d often walked that far and back across Toronto in his lunch hour. But the area was eight times greater than the total of the two islands they’d toiled on for six days each, and when he saw the dense jungle stretching back from the beach into low wooded hills, he finally felt the scale of it. It was a far more visceral reaction than anything he’d experienced flying over an ocean or a continent. Probably because Grant would want to gather samples from every last square metre.
They found a gap in the reef almost straight ahead as they approached. It was early afternoon, but Prabir begged for a full day off before they went ashore. They ended up spending three hours snorkelling along the reef, taking pictures but collecting no samples: Grant’s licence didn’t extend to the marine life, and so far there’d been no sign that the mutations did either.
Prabir couldn’t help feeling tranquil in the sunlit water; it was impossible to remain uncharmed by the colours of the reef fish, or the weird anatomy of the invertebrates clinging to the coral. Everything here was beautiful and alien, dazzling and remote. A thousand delicate, translucent fish larvae could die in front of him without evoking the slightest twinge of compassion, the kind of thing a chick or a rat pup in the beak of a hawk would have produced. It was this distance that made the spectacle seem so much purer than anything on land: the same vicious struggle looked like nothing but a metaphorical ballet. If his roots were here, he had no sense of it; his body had built its own tamed sea and escaped to another world, as surely as if it had ascended into interstellar space, too long ago to remember.
Sitting on the deck beside Grant in silence, the salt water drying on his skin, Prabir felt calm, lucid, hopeful. The past was not an immovable anchor. What evolution had done, design could do better. There would always be a chance to take what you needed, take what was good, then cut yourself free and move on.
The jungle was as lush as anything Prabir had seen, but without quantifying the impression with a count of species, it also struck him as impoverished. The thorned shrubs and the giant orchids were evident in abundance, but there was nothing at all in sight that merely resembled them. No close relatives, only the things themselves. Whatever else Grant’s theory had trouble explaining, you couldn’t wind the clock back on a set of surviving lineages and expect to maintain the diversity you started with, and here you could practically see the ancestral bottlenecks everywhere you looked.
Grant called him over. She’d found an orchid clamped shut around the corpse of a small bird, bright-blue tail feathers protruding.
Prabir said, ‘I wish you hadn’t shown me this.’
‘Forewarned is forearmed. What I really want to know is—’ Grant sank her knife into the white petals and tore the shroud open.
Ants poured from the gash. As she pulled the knife away, the skeleton of the bird sagged down from the flower, swarming with them.
She inhaled sharply. ‘OK. But is that just opportunism?’ She cut the flower again, then extended the incision down into the stem.
There was a hollow core, full of ants. Grant handed Prabir the camera, and he recorded everything as she continued the dissection, following the stem around the trunk five times until she’d laid the whole internal city bare. There were chambers full of foamy white eggs, and a bloated queen the size of a human thumb.
Prabir said, ‘What does the orchid get out of it?’
‘Maybe just food scraps and excrement; that could be more than enough. Or maybe the ants are feeding it something specific, some secretion tailor-made to keep it happy and fit.’ Grant was clearly elated, but then she added wistfully, ‘Someone’s going to spend a lifetime on this.’
‘Why not do it yourself?’
She shrugged. ‘Not my style. Begging to foundations for charity to do something beautiful and useless.’
Prabir felt like grabbing her by the shoulders and shaking her; this sounded so defeatist. He said, ‘Maybe in a few years you’ll feel differently. Once you’re not facing the same financial pressures—’
Grant pulled a face. ‘Don’t organise me; I hate that. No wonder your sister ran away from home.’
Prabir crouched down beside the orchid. ‘First mimicry, now symbiosis. These gene-recovery enzymes of yours can hit a bull’s-eye at fifty million years.’
‘And don’t gloat, it doesn’t suit you. I admit it, freely: there’s something going on here that I don’t understand.’
Prabir said, ‘I still think your basic idea must be right. Functional genes take thousands of years to develop. If they appear overnight, the organism has to be cheating. “Here’s one I prepared earlier.” What else can it be?’
Grant seemed ready to accept this, but then she shook her head. ‘I can’t answer that, but it’s starting to look as if I’m missing something fundamental. Perfectly camouflaged birds with no predators. Thorned plants with nothing even trying to munch on them. There are misses as well as bull’s-eyes. But even the misses are too precise.’
She squatted beside Prabir. The ants were methodically criss-crossing the tear in the stem, secreting a papier-mâché-like scaffolding a thousand times faster than any plant could have grown new tissue. She said, ‘Don’t you wish you could just ask them for the whole story? When did they get together and sort this all out?
Why did they stop? Why did they start again? What is it we don’t understand?’
It was late morning on the second day when they reached the mangrove swamp. They were at least a kilometre inland, but there was a narrow valley running from the heart of the jungle to the coast, its floor a would-be river bed with too little runoff feeding it to prevent sea water flooding in at high tide. At low tide, the halophytic trees would stand naked in an expanse of salty mud, but that was still hours away; for now, the way ahead was inundated.
Grant peered into the tangle of branches and aerial roots. ‘It’s only a few hundred metres across. We should be able to wade through without too much trouble.’
‘And then time it so we can cross back at low tide?’
‘Yeah.’
Prabir found that part appealing; if they had to do this at all, he’d rather do it while he still had the energy.
He double-checked that all the sample tubes he was carrying were sealed; his watch and notepad were fully waterproof. There didn’t seem much point taking any of his clothes off; they’d get coated in slime however he carried them, and the more protection he had against scrapes and splinters from the roots, the better.
Grant waded in up to her knees. Prabir followed her, every step like an exaggerated mime of walking as his boots stuck afresh in the mud. The water was turbid with silt, almost opaque where it could be seen at all, but most of the surface was covered with a layer of algae and dead leaves. The odour of salt and decay was insistent – like breathing over a garden compost heap with seaweed added for effect – but not overpowering or stomach-turning. Other parts of the forest had smelt worse.
The protruding brown roots of the mangroves were dotted with snails, but Prabir spotted small brown crabs as well. Clouds of mites and mosquitoes approached them and then backed away; at least their repellent was holding out. The trees were twenty or thirty metres tall; it was eerie to look up into the branches, decorated with small white blossoms and tiny green fruit, then down into what was essentially dirty sea water, as if a forest had sprouted in the middle of the ocean.