Danchekker had reasoned that a violent mutation had taken place along the line of human descent isolated on Minerva. This latest piece of information pointed out the area in which the mutation had occurred; it didn't attempt to explain why it had happened. But then, mutations are random events; there was nothing to suggest that there had been any specific cause to look for.
The evident fact of the emergence of Ganymean intelligence fitted in nicely with this body of theory too. The architecture of Minervan land dwellers had isolated the system that carried the toxins from the system that carried blood. Thus, when larger brains became in order, the way was clear to evolve a brain that could draw more blood without more toxins--the density of one network simply increased while that of the other didn't. Higher brain functions could develop without hindrance. The intelligence of the Ganymeans was the natural and logical outcome of Minervan evolution. Terrestrial evolution, however, pointed to no such natural and logical outcome; Man had somehow cheated the system.
"Well," Hunt declared finally. "It's interesting, sure. But what makes you say it shouldn't have happened? Mutations are random events. The change came about as a mutation that took place on Minerva, somewhere along the line that led to the Lunarians and from there to Man. It looks straightforward. What's wrong with that?"
"I thought you'd say that," ZORAC commented, somehow managing to give the impression of sounding quite pleased with itself. "That's the obvious first reaction."
"So--what's wrong with it?"
"It couldn't work. What you're saying is that somewhere early on in the primate line on Minerva, a mutation must have occurred that deactivated the self-immunization system."
"Yes," Hunt agreed.
"But there's a problem in that," ZORAC advised him. "You see, I have performed extensive computations on further data available from J5--data that describe the genetic coding contained in vertebrate chromosomes. In all species, the coding that controls the development of the self-immunization process in the growing embryo contains the coding that enables the animal specifically to absorb excess carbon dioxide. In other words, if you deactivated the self-immunization mechanism, you'd also lose the ability to tolerate a C02 -rich environment. . . ."
"And Minerva was becoming CO2 -rich," Hunt supplied, seeing the point.
"Exactly. If a mutation of the kind you're suggesting occurred, then the species in which it had occurred could not have survived on Minerva. Hence, the ancestors of the Lunarians could not have mutated like that. If they did, they'd have died out. The Lunarians would never have existed and you wouldn't exist."
"But I do," Hunt pointed out needlessly, but with a certain sense of satisfaction.
"I know, and you shouldn't, and that's my question," ZORAC concluded.
Hunt stubbed out his cigarette and lapsed into thought again. "What about the funny enzyme that Chris Danchekker is always talking about? He found it in all the preserved Oligocene animals in the ship here, didn't he? There were traces of a variant of it in Charlie too. D'you reckon that could have something to do with it? Maybe something in the environment on Minerva reacted in some complicated way and got around the problem and the enzyme appeared somehow in the process. That would explain why today's terrestrial animals haven't got it; the ancestors they're descended from never went there. Perhaps that's why modern Man doesn't have it either--he's been back on Earth for a long time now and away from the environment that stimulated it. How about that?"
"Impossible to confirm," ZORAC pronounced. "Inadequate data available on the enzyme at present. Very speculative. Also, there's another point it doesn't explain."
"Oh, what?"
"The radioactive decay residues. Why should the enzymes found in the Oligocene animals appear to have been formed from radioisotopes while the ones found in Charlie didn't?"
"I don't know," Hunt admitted. "That doesn't make sense. Anyhow, I'm not a biologist. I'll talk about all this to Chris later." Then he changed the subject. "ZORAC--about all those equations you computed."
"Yes?"
"Why did you compute them? I mean. . . do you just do things like that spontaneously. . . on your own initiative?"
"No. Shilohin and some of the other Ganymean scientists asked me to."
"Any idea why?"
"Routine. The computations were relevant to certain researches that they are conducting."
"What kind of researches?" Hunt asked.
"On the things we have been discussing. The question that I suggested a few minutes ago was not something that I originated myself; it was a question that they have been asking. They are very interested in the whole subject. They're curious to find out how Man came to exist at all when all available data says he shouldn't and all their models predicted that he would destroy himself if he did."
Hunt was intrigued to learn that the Ganymeans were studying his kind with such intensity, especially since they appeared to have progressed so much further in their deductions than the UNSA team had. He was surprised also that ZORAC would so readily divulge something that could be considered sensitive information.
"I'm amazed that there aren't any restrictions on you talking about things like that," he said.
"Why?"
The question caught Hunt unprepared.
"Oh, I don't know really," he said. "On Earth I suppose things like that would only be accessible to people authorized. . . certainly not freely available to anyone who cared to ask for it. I suppose I. . . just assumed it would be the same."
"The fact that Earthmen are neurotic is no reason for Ganymeans to be furtive," ZORAC told him bluntly.
Hunt grinned and shook his head slowly.
"I guess I asked for that," he sighed.
Chapter Sixteen
The first and most important task that the Ganymeans had faced--that of getting their ship in order again--had now been successfully accomplished. So the focal point of their activities shifted to Pithead, where they commenced working intensively toward their second objective--coming to grips with the computer system of the wrecked ship. Whether the Ganymean race had migrated to another star, and if so which star, had still not been answered. A strong probability remained that this information was sitting waiting to be found, buried somewhere in the intricate molecular circuits and storage banks that went to make up the data-processing complex of a ship that had been built after the answers to these questions were known. The ship might even have been involved in that very migration.
The task turned out to be nowhere near as straightforward as the first one. Although the Pithead ship was of a later and more advanced design than the Shapieron , its main drives worked on similar principles and used components which, although showing certain modifications and refinements in some instances, performed functions that were essentially the same as those of their earlier counterparts. The drive system thus exemplified a mature technology that had not changed radically between the times of the two ships' construction, and the repair of the Shapieron had been possible as a consequence.
The same was not true for the computer systems. After a week of intensive analysis and probing, the Ganymean scientists admitted they were making little headway. The problem was that the system components that they found themselves trying to comprehend were, in most cases, unlike anything they had seen before. The processors themselves consisted of solid crystal blocks inside which millions of separate circuit elements of molecular dimensions were interconnected in three dimensions with complexities that defied the imagination. Only somebody who had been trained and educated in the design and physics of such devices could hope to unravel the coding locked inside them.