‘Fine,’ said Li. ‘But what about single-cell organisms?’
‘The same thing applies,’ said Rubin. ‘If their DNA mutates, it has to be repaired. And remember, organisms like that reproduce by cell division. For a species to remain stable, its DNA has to undergo repair. It doesn’t matter what kind of cells we’re talking about, nature always endeavours to keep the rate of mutation within manageable limits. And that’s the catch for Anawak’s theory. The genome is repaired globally, along its entire length. You can picture the repair enzymes as policemen, patrolling the entire DNA strand on the look-out for errors. As soon as they find a defective area, they begin the repair. To ensure that the information corresponding to the DNA’s original sequence doesn’t get lost, the repair enzymes act as the guardians of the genome’s data. They police the sequence and can tell immediately which genetic configurations match the original and which are defective. It’s like trying and failing to teach a child to talk. As soon as it learns a new word, the repair enzymes come along and reprogram it to its original state - ignorance. It’s not possible for it to learn.’
‘Then Anawak’s theory is nonsense,’ said Li. ‘It would only make sense if the amoebas could retain the changes to their DNA.’
‘Well, on the one hand, that’s right. Any new information would be treated as defective by the repair enzymes and, hey presto, the genome’s restored to its original configuration. Back to square one, so to speak.’
‘I’m guessing,’ grinned Vanderbilt, ‘that we’re about to hear the but.’
Rubin nodded hesitantly. ‘There is one,’ he said.
‘Which is?’
‘I don’t know.’
‘Hang on,’ said Peak. He sat up in his chair and winced. His foot was bandaged. ‘I thought you just said—’
‘I know! But the theory’s brilliant,’ cried Rubin. ‘It would explain everything. Then we’d be certain that the substance in the tank is our enemy. We’d be face to face with the yrr - the creatures that have landed us in all this shit. And I’m certain that it’s them! We saw some pretty weird stuff in the lab this morning. The blob of jelly examined our robot, and you should have seen the way it did it - it had nothing to do with animal instinct or curiosity. It was pure cognitive intelligence. Anawak’s theory must be right. Weaver’s already got it working electronically.’
‘But how are we supposed to make sense of it?’ Vanderbilt sighed and mopped his forehead.
‘It could be to do with anomalies.’ Rubin gestured vaguely. ‘Even repair enzymes sometimes make mistakes. Not often, but every ten thousand repairs or so they slip up. They miss a base pair that should have been restored to its original state. It’s not much, but it’s enough to cause a baby to be born haemophiliac, with a cleft palate or even cancer. We see these anomalies as defects, but they’re proof that the repair mechanism doesn’t always work.’
Li got up and paced slowly round the room. ‘So you believe that the amoebas and the yrr are one and the same. We’ve found our adversary.’
‘With two provisos,’ Rubin added. ‘First, we have to solve the DNA conundrum, and second, there has to be some kind of queen-yrr. No doubt the collective is highly intelligent, but I reckon the stuff we’ve got down there is only the executive part of the whole.’
‘A queen-yrr? How do you envisage it?’
‘Well, the same and yet different. A bit like ants. The queen-ant is an ant, but a special one. She’s at the heart of everything. The yrr are swarming organisms, you see - collectives of amoebas. If Anawak’s right, they embody an alternative evolutionary path for intelligent life, but something must be guiding them.’
‘So if we were to find this queen…’ Peak began.
‘No.’ Rubin shook his head. ‘There’s no point in fooling ourselves. There could be more than one - there could be millions. And if they’re smart, they won’t come anywhere near us.’ He paused. ‘But to be queens, they’d necessarily share the same basic principles as the rest of the yrr. They’d aggregate, and they’d have genetic memory. We’re in the process of isolating a chemical that the amoebas give off as a signal to start aggregating. Oliviera and Johanson are on the brink of working out its formula. And you can bet that this chemical, this pheromone, will also cause the queens to aggregate with the yrr too. Scent is the key to yrr communication.’ Rubin gave a self-satisfied smile. ‘And it could be the answer to all our problems.’
‘Thank you, Mick.’ Vanderbilt inclined his head towards him graciously. ‘You’re in our good books again - for the time being at least. Even if you did screw up on the well deck.’
‘That wasn’t my fault.’ Rubin sounded offended.
‘You’re in the CIA, Mick. In my team. And in my team the buck always stops with you. Did we forget to mention that when we hired you?’
‘No.’
Vanderbilt shoved his handkerchief clumsily into his trouser pocket. ‘I’m glad to hear it. Jude’s about to call the President so she’ll be able to tell him what a good boy you’ve been. Thanks for paying us a visit. Now, run along back to work.’
Flag Command Center
Crowe and Shankar didn’t look anywhere near as self-assured as they had when they’d decoded the first signal. Team morale was low, which was only due in part to the terrible events on the well deck. It was becoming increasingly obvious that no one understood the yrr’s strategy.
‘Why send us a message and then attack us?’ asked Peak. ‘Humans wouldn’t do that.’
‘You’ve got to stop thinking in those categories,’ said Shankar. ‘They’re not humans.’
‘I’m just trying to understand.’
‘Well, you never will, if you keep basing your ideas on human logic,’ said Crowe. ‘Maybe their first message was a warning. We know where you are. That’s what their reply comes down to.’
‘Maybe it was a diversionary tactic,’ suggested Oliviera.
‘But what would be the point?’ asked Anawak.
‘To distract us?’
‘From what? From the fact that they were about to light up outside like a Christmas tree?’
‘It’s not as crazy as it sounds,’ said Johanson. ‘They certainly achieved one thing. They got us thinking they were interested in dialogue. Sal’s right: people wouldn’t act like that, and maybe the yrr know it. So they lulled us into a false sense of security, showed themselves in all their glory, and while we were blithely expecting a cosmic revelation, they gave us a kick in the teeth.’
‘Maybe sending them a couple of lousy math questions wasn’t such a great idea,’ said Vanderbilt to Crowe.
Crowe lost her cool. Her eyes flashed. ‘Do you have a better suggestion?’
‘It’s not my job to make suggestions,’ said Vanderbilt, spoiling for a fight. ‘That’s your job. Making contact is your responsibility.’
‘Making contact with whom? You won’t accept it’s not a plot by rebel mullahs.’
‘If all you can achieve with your crappy messages is to give away our location, that’s your problem and you’re going to have to fix it. You sent the enemy detailed information about the human race. You practically told them to attack.’
‘You have to know who you’re dealing with before you can negotiate,’ Crowe hissed back. ‘It’s about time you understood that, you moron. I need to know who they are, which is why I’m telling them about us.’
‘All this message shit is a dead end—’
‘For Christ’s sake, we’ve only just started!’
‘Just like your jumped-up SETI hogwash was a dead end too. Only just started? Well, congratulations - how many people are going to die when you really get going?’
‘Jack,’ snapped Li.
‘This contact crap is—’
‘That’s enough! I don’t want arguments, I want results. So let’s hear from someone who’s got something to report.’
‘We’ve got something,’ Crowe said sullenly. ‘The second message is based around a formula, the chemical formula for wate
r. We’ll find out what the rest of it means in due course - if we’re allowed to work in peace.’
‘We’ve made a bit of headway too,’ Weaver added.
‘So’ve we!’ Rubin was in there like a shot. ‘We’ve made a massive leap forwards, thanks to the, uh, assistance of Sigur and Sue.’ He coughed. ‘Maybe you’d like to explain, Sue?’
‘You’re too kind,’ she muttered. To the others she said, ‘We’ve managed to isolate the chemical that causes the cells to aggregate. It’s a pheromone, and we know how it works. Sigur can take the credit for that - he dared to do battle with the monster to get those tissue samples.’
She put a sealed container on the table. It was half full of a watery liquid.
‘The yrr scent is in here. We’ve analysed it and we’re able to synthesise it. The formula is surprisingly simple. We’re still not a hundred per cent sure exactly how they use it to make contact or who or what initiates the aggregation. But assuming that something’s able to trigger it - and, for the sake of argument, I’m going to call that something the queen - there’s the question of how it summons millions and billions of free-floating amoebas who don’t have eyes or ears. That’s what this pheromone is for. Chemicals aren’t especially suited for communication under water - the molecules disperse too quickly. But over short distances pheromone signals work brilliantly. And, as far we can tell, the amoebas’ pheromonal communication is restricted to this one chemical. There’s no language, just a single word: aggregate! We’re not sure how they keep communicating after they’ve aggregated. All we can say for certain is that there’s some form of information exchange. It’s no different from a neural network computer or a human brain. The individual units need messengers working between them. In biology, they’re called ligands. If a cell wants to pass information to another cell, it can’t just wander over and tell it so it sends a message via the ligands to the other cell. And when the ligands get to the cell, it’s like arriving at any civilised house: they come to a door with a bell - scientifically speaking, a receptor. The ligands ring the bell, and the message is carried through a cascade of signals to the centre of the cell, where the information is passed to the genome.’
She paused.
‘The amoebas in the tank also seem to communicate using ligands and receptors. Of course, the idea that cells are like houses with doorbells and helpful messengers is a little misleading. Each cell emits not just one but a cloud of molecules, and cells don’t just have a single receptor - they’ve got something in the region of two hundred thousand. That’s how they pick up the pheromones and dock on to the collective. That’s two hundred thousand doorbells to help them communicate with their neighbouring cells! It’s pretty impressive. The process of aggregation takes place like a relay - one cell picks up pheromones from the collective and attaches itself to the neighbouring cells, all the time sending out new pheromones to reach the other cells floating in the water around it, and so it goes on. It progresses from the centre outwards. For the sake of simplicity, let’s skip a few stages of the argument and contend that the cells we’ve been looking at are indeed our formidable enemy, the yrr.’
She pressed her fingertips together.
‘What struck us right away was that the cells don’t merely have receptors, they have pairs of receptors. We racked our brains trying to figure out why, and then we cracked it: it’s about ensuring the collective stays healthy. We labelled the receptors according to their function. The universal receptor says, I am the yrr. The special receptor says, I am a fully functioning healthy yrr-amoeba with intact DNA, worthy of being part of the collective and ready to take part in the pow-wow.’
‘But couldn’t you achieve that through a single receptor?’ asked Shankar, with a frown.
‘No. Probably not,’ said Oliviera. ‘It’s actually an ingenious system. According to our model, a yrr-amoeba is rather like a military camp fenced in by a wall. Any soldier approaching from the outside is identified by a universal marker: his uniform. The uniform tells the other soldiers in the camp, I’m one of you. But those of you who’ve seen your Michael Caine war movies will know that uniforms are sometimes a disguise. Once your camp’s been infiltrated by an outsider, your lives are in danger. So if Michael Caine’s to be admitted, he has to know the special signal too. He needs the password. How am I doing from a military point of view, Sal?’
Peak gave a nod. ‘Absolutely right.’
‘Thank goodness for that. So, when the yrr join together, the following occurs: yrr that have already aggregated produce a scent molecule, a pheromone. The pheromone reaches the other cells’ universal receptors and initiates the primary connections; I am the yrr. The first part of the identification process has taken place. The second step requires the special receptors to receive the message, I am a healthy yrr. Well, that’s all very well, but some yrr-cells aren’t fully operational or healthy. In other words, they’ve got defective DNA. Since our adversary exists in swarms of billions and seems able to evolve continually, it has to weed out any yrr-cells that aren’t capable of further development. The trick seems to be that while every amoeba has a universal receptor, only healthy ones capable of development are in possession of the special receptor. Defective cells don’t have them. And now comes the really surprising bit, the bit that should make us afraid. Defective yrr don’t know the password. They’re excluded from the aggregation. But that’s not enough. Yrr are amoebas, and like all amoebas they reproduce by cell division. A species that’s continually learning and evolving obviously can’t allow a second, defective, population to come into being, so it has to act quickly to stop faulty cells reproducing. That’s when the pheromone reveals its dual purpose. In the event that a defective yrr is rejected, the pheromone clings to the amoeba’s universal receptor and serves as a fast-acting toxin. It induces programmed cell death, a phenomenon otherwise unheard of in single-cell organisms. The faulty yrr-cell dies at once.’
‘How can you tell it’s dead?’ asked Peak.
‘Easy. Its metabolism stops. Besides, you can recognise a dead yrr because it stops glowing. For yrr, luminescing is a biochemical necessity. The best-known example of marine bioluminescence is probably the Aequorea, a hydromedusa from the South Seas. It glows when it produces a pheromone. A similar process is going on here. Pheromones are released by the yrr, causing them to glow. The flashes of light are a sign of particularly intense biochemical activity within the aggregated cells. When yrr luminesce, they’re communicating and thinking. When they die, the light goes out.’
Oliviera looked at the others. ‘So here’s why we need to be afraid. The yrr use basic means to run a complex system of selection. If a yrr-amoeba is healthy and has a fully functioning pair of receptors, the pheromone triggers aggregation. But if that amoeba lacks a special receptor, the pheromone takes its deadly toll. The point is, a species that works like this has a very different perspective on death. Death in yrr society is vital. It would never occur to the yrr to spare a defective yrr-cell. To them it would seem absurd - stupid, even. It’s imperative for them to destroy the threat to their own evolution. Whenever the collective is threatened, the yrr respond with the logic of death. It’s no good pleading for mercy or expecting compassion. The logic of death doesn’t make exceptions, and it’s not about brutality. Such thoughts are alien to the yrr and, as such, they’ll never understand why they should spare us - given that we’re a concrete threat.’
‘Uh-huh. So their biochemistry imposes a different morality,’ said Li.
‘Well, I dare say that’s very interesting,’ interrupted Vanderbilt, ‘but what does it matter if they all use Chanel No. 5 or whatever? I mean, what’s the point of knowing that? We could all go and aggregate with them. Yeah, that’s it, I’ll club together with some yrr.’
Crowe gave him a withering look. ‘Like they’d let you.’
‘Oh, screw you, Crowe.’
‘You guys can keep fighting if you like,’ said Anawak, ‘but Karen and I have an idea about how yrr co
gnition might work. We’ve got Sigur, Mick and Sue pulling their hair out over it. Biologically, it’s nonsense - but it would answer a whole heap of questions.’
Weaver took over. ‘We programmed our virtual amoebas with electronic DNA, and set it up to keep mutating. In other words, the DNA was learning. All of a sudden we found ourselves back where we’d started–with a functioning neural network computer. We’d originally split our electronic brain into its smallest programmable units and tried to put them back together again as a thinking whole. It didn’t work, or at least not until the individual cells were capable of learning. But the only way that a biological cell could learn is through mutations in its DNA, and that’s unheard of - but it’s exactly what we told our virtual cells to do. We used a scent, like Sue described.’
‘The thing is,’ Anawak continued, ‘We didn’t just get our fully functioning neural network computer back: we had yrr operating within their natural habitat. Our version of the network came with a few added extras - we allowed the cells to move through three-dimensional space. It replicated deep-sea conditions, with pressure, currents, friction and so on. First, we had to answer the question as to how members of a collective are able to recognise each other. The pheromone is only half of the story. The rest involves limiting the size of the collective. And that’s where Sue and Sigur’s discovery comes into play. They found that yrr amplicons differ from each other in small, hypervariable sections, so, as we said before, the cells would have to change their DNA after they came into being. Well, we think that’s exactly what happens, and that these hypervariable sections serve as a code for them to recognise each other and to know which collective they belong to.’
‘Yrr-amoebas with the same coding recognise each other, and small collectives can aggregate with larger ones,’ said Li.
The Swarm: A Novel Page 87