Mancini spent more than an hour at his rather revolting task before he finally laid down his instruments. Stubbs had not been able to watch him the whole time, since the Shark had picked up the other two unresponsive whales while the job was going on. Both had been infected in the same way as the first. The boy was back in the lab, though, when the gross dissection of the original one was finished. So was Winkle, since nothing more could be planned until Mancini produced some sort of report.
“The skeleton was gone completely,” was the mechanic's terse beginning. “Even the unborn one hadn't a trace of metallic iron in it. That was why the magnets didn't hold, of course. I haven't had time to look at any of the analysis reports, but I'm pretty certain that the jelly in the body cavity and the moldy stuff outside are part of the same life form, and that organism dissolved the metallic skeleton and precipitated the iron as magnetite in its own tissues. Presumably it's a mutant from one of the regular iron-feeding strains. Judging by its general cellular conformation, its genetic tape is a purine-pyrimidine nucleotide quite similar to that of natural life…"
“Just another of the original artificial forms coming home to roost?” interjected Winkle.
“I suppose so. I've isolated some of the nuclear material, but it will have to go back to the big field analyzer on the Guppy to make sure.”
“There seem to be no more damaged fish in the neighborhood. Is there any other material you need before we go back?”
“No. Might as well wind her up, as far as I'm concerned — unless it would be a good idea to call the ship first while we're out here to find out whether any other schools this way need checking.”
“You can't carry any more specimens in your lab even if they do,” Winkle pointed out, glancing around the littered bench tops.
“True enough. Maybe there's something which wouldn't need a major checkup, though. But you're the captain; play it as you think best. I'll be busy with this lot until we get back to the Guppy whether we go straight there or not.”
“I'll call.” The captain turned away to his own station.
“I wonder why they made the first pseudolife machines with gene tapes so much like the real thing,” Stubbs remarked when Winkle was back in his seat. “You'd think they'd foresee what mutations could do, and that organisms too similar to genuine life might even give rise to forms which could cause disease in us as well as in other artificial forms.”
“They thought of it, all right,” replied Mancini. “That possibility was a favorite theme of the opponents of the whole process — at least, of the ones who weren't driven by frankly religious motives. Unfortunately, there was no other way the business could have developed. The original research of course had to be carried out on what you call 'real' life. That led to the specific knowledge that the cytosine-thiamine-adenine-guanine foursome of ordinary DNA could form a pattern which was both self-replicating and able to control polypeptide and polysaccharide synthesis…"
“But I thought it was more complex than that; there are phosphates and sugars in the chain, and the DNA imprints RNA, and…"
“You're quite right, but I wasn't giving a chemistry lecture; I was trying to make an historical point. I'm saying that at first, no one realized that anything except those four specific bases could do the genetic job. Then they found that quite a lot of natural life forms had variations of those bases in their nucleotides, and gradually the reasons why those structures, or rather their potential fields, had the polymer molding ability they do became clear. Then, and only then, was it obvious that 'natural' genes aren't the only possible ones; they're simply the ones which got a head start on this planet. There are as many ways of building a gene as there are of writing a poem — or of making an airplane if you prefer to stay on the physical plane. As you seem to know, using the channels of a synthetic zeolite as the backbone for a genetic tape happens to be a very convenient technique when we want to grow a machine like the one we've just taken apart here. It's bulkier than the phosphate-sugar-base tape, but a good deal more stable.
“It's still handy, though, to know how to work with the real thing — after all, you know as well as I do that the reason you have a life expectancy of about a hundred and fifty years is that your particular gene pattern is on file in half a cubic meter of zeolite mesh in Denver under a nice file number…”
“026-18-5633,” muttered the boy under his breath.
“…which will let any halfway competent molecular mechanic like me grow replacement parts and tissues if and when you happen to need them.”
“I know all that, but it still seems dangerous to poke around making little changes in ordinary life forms,” replied Rick. “There must be fifty thousand people like you in the world, who could tailor a dangerous virus, or germ, or crop fungus in a couple of weeks of lab and computer work, and whose regular activities produce things like that iron-feeder which can mutate into dangerous by-products.”
“It's also dangerous to have seven billion people on the planet, practically every one of whom knows how to light a fire,” replied Mancini. “Dangerous or not, it was no more possible to go from Watson and Crick and the DNA structure to this zeowhale without the intermediate development than it would have been to get from the Wright brothers and their powered kite to the two-hour transatlantic ramjet without building Ford tri-motors and DC-3's in between. We have the knowledge, it's an historical fact that no one can effectively destroy it, so we might as well use it. The fact that so many competent practitioners of the art exist is our best safeguard if it does get a little out of hand at times.”
The boy looked thoughtful.
“Maybe you have something there,” he said slowly. “But with all that knowledge, why only a hundred and fifty years? Why can't you keep people going indefinitely?”
“Do you think we should?” Mancini countered with a straight face. Rick grinned.
“Stop ducking. If you could, you would — for some people anyway. Why can't you?” Mancini shrugged.
“Several hundred million people undoubtedly know the rules of chess.” He nodded toward the board on Dandridge's control table. “Why aren't they all good players? You know, don't you, why doctors were reluctant to use hormones as therapeutic agents even when they became available in quantity?”
“I think so. If you gave someone cortisone it might do what you wanted, but it might also set other glands going or slow them down, which would alter the levels of other hormones, which in turn…well, it was a sort of chain reaction which could end anywhere.”
“Precisely. And gene-juggling is the same only more so. If you were to sit at the edge of the hatch there and let Gil close it on you, I could rig the factors in your gene pattern so as to let you grow new legs; but there would be a distinct risk of affecting other things in your system at the same time. In effect, I would be taking certain restraints which caused your legs to stop growing when they were completed off your cell-dividing control mechanisms — the sort of thing that used to happen as a natural, random effect in cancer. I'd probably get away with it — or rather, you would — since you're only about nineteen and still pretty deep in what we call the stability well. As you get older, though, with more and more factors interfering with that stability, the job gets harder — it's a literal juggling act, with more and more balls being tossed to the juggler every year you live.