Hunt had stopped pacing and was now looking down at Danchekker with a slow frown spreading across his face, as if another thought had just struck him.
"But there's something else, isn't there?" he said. "The self-immunization process has something to do with higher brain functions. . . . Are you saying what I think you're saying?"
"I suspect so. As you know, the toxins introduced into the body by the self-immunization process in today's animals has the effect of inhibiting the development of the higher brain centers. And another thing--Tatham's latest work indicates that, because of the way terrestrial life happens to have evolved, the capacity for violence and aggression is closely related to the development of those centers too. Thus, the Ganymeans would have found themselves unable to produce variants of the type they wanted without also removing the inhibition on the development of higher brain functions, and in addition producing an enhanced tendency toward aggression. That being the case and the Ganymeans being the way they were, I can't really see them taking the experiment any further. They would never have risked introducing anything like that into themselves, whatever the urgency of the situation. Never."
"So they gave the whole thing up as a bad job in the end and went off to pastures new," Hunt completed.
"Maybe, and again maybe not. We have no way of telling for sure. I certainly hope so for the sake of Garuth and his friends." Danchekker leaned forward on the desk and at once his mood became more serious. "But whatever the answer to that is, at least we have a definite answer to another of the questions that you asked at the beginning."
"Which one?"
"Well, consider the situation that must have existed on Minerva when the Ganymeans came to the point of accepting that their ambitious genetic engineering solution was running into trouble. They could go away to another star or stay on their own world and perish. Either way, the days of the Ganymean presence on Minerva were numbered. Now take them out of the equation, and what is left? Answer--two populations of animals both of which are well adapted to handling the environmental conditions. First there are the native Minervan types, and second the artificially mutated descendants of the imported terrestrial types, free to roam the planet after the departure of the Ganymeans. Now return to the equation one further factor that I have established through long interrogation of ZORAC's archives--the native Minervan species would not have been poisonous to terrestrial carnivores--and what do you conclude?"
Hunt gazed back with eyes that were suddenly aghast.
"Christ!" he breathed. "It would have been a bloody slaughter."
"Yes, indeed. Consider a planet inhabited only by those ridiculous Technicolored cartoon animals that we found drawn on the walls of that ship at Pithead--animals that had never evolved any specializations for defense, concealment or escape, and which had no need for fight-or-flight instincts at all. Now throw in among them a typical mix of predators from Earth--every one a selected product of millions of years of improvement of the arts of ferocity, stealth and cunning. . . added to which they were evolving higher levels of intelligence that had previously been inhibited and their already fearsome aggressiveness was being further reinforced. Now what picture do you see?"
Hunt just continued to stare in horrified silence as the picture unfolded before his mind's eye.
"That's what wiped them all out," he said at last. "That poor bloody Minervan zoo wouldn't have had a chance. No wonder it didn't last for more than a few generations after the Ganymeans disappeared from the scene."
"With another consequence as well," Danchekker came in. "The terrestrial carnivores concentrated on the most readily available prey--the native species--and so gave the terrestrial herbivores a breathing space to increase their numbers and become firmly established. By the time the Minervan natives had been wiped out the carnivores would have been forced to revert to their old habits, but by that time the situation would have stabilized. A mixed and balanced terrestrial animal ecology had been given time to establish itself across Minerva. . . ." The professor's voice took on a soft and curious tone. "And that is the way things must have remained . . . right on through until the time of the Lunarians."
"Charlie. . ." Hunt sensed that Danchekker was at last hinting at something he had been building up to all along. "Charlie," Hunt repeated. "You found that same enzyme in him too, didn't you?"
'We did, but in a somewhat degenerate form. . . as if it were in the last phases of fading away completely. It did fade away of course, since Man no longer possesses it. . . . But the interesting point, as you say, is that Charlie had it and so, presumably, did the rest of the Lunarians."
"And there was only one place for it to come from. . ."
"Precisely."
Hunt raised a hand to his brow as the full import of these revelations hit him. He turned slowly to meet Danchekker's solemn gaze and then slowly, his features knotted into a mask of disbelief that strove to reject the things that reason now stripped bare, sank weakly down onto an arm of the nearest chair. Danchekker said nothing, waiting for Hunt to put the pieces together for himself.
"The population on Minerva included samples of the latest Oligocene primates," Hunt said after a while. "They were almost certainly as advanced as anything that Earth had produced at the time, and with the greatest potential for advancing further. The Ganymeans had unwittingly removed the inhibition on further brain development. . . ." He looked up and met Danchekker's imperturbable stare again. "They'd have raced ahead from there. There was nothing to stop them. And with their aggressive streak unleashed as well. . . a whole race of runaway mutants. . . psychological Frankenstein monsters. . . ."
"Which is, of course, where the Lunarians came from," Danchekker said. His voice was grave. "By rights they shouldn't have survived. All the theories and models of the Ganymean scientists said that they would inevitably destroy themselves. They almost did. They turned a whole planet into one vast fortress and by the time they had developed technology their lives revolved around unceasing warfare and the ruthless, uncompromising determination to exterminate all other rival states. They were capable of conceiving no other formula to solve their problems. In the end they did indeed destroy themselves and Minerva along with them, at least, they destroyed their civilization, if that is the correct term for it. They should have destroyed themselves totally, but, by a million-to-one chance, it did not quite happen. . . ." Danchekker looked up and left Hunt to fill in the rest.
But Hunt just sat and stared, overwhelmed. After the nuclear holocaust between the opposing forces of the two remaining Lunarian superstates had altered permanently the face of Minerva's moon and Minerva had disintegrated, the moon fell inward toward the Sun to be captured by Earth. The tiny band of survivors carried with it had possessed the resources to set off one last, desperate journey--to the surface of the new world that now hung in the sky above their heads. For forty thousand years the descendants of those survivors had merged into the survival struggle of Earth, but eventually they had spread all over the planet and emerged as an adversary as formidable as their ancestors had been on Minerva.
At last, Danchekker resumed quietly. "We have speculated for some time now that the Lunarians, and hence Man, originated from an unprecedented mutation that must have occurred somewhere along the primate line that was isolated on Minerva. Also, we have noted that somewhere along his line of ancestry, Man has somehow abandoned the self-immunization process that other animals have in common. Now we see not only proof that these things were true, but also how they came about. In fact, many species went along that same path, but all bar one were destroyed when Minerva was destroyed. Only one--Man in the form of the Lunarians--came back again." Danchekker paused and took a long breath. "An unprecedented mutation did indeed occur on Minerva, but it was not a natural mutation. Modern Man exhibits fewer of the extremes that drove the Lunarians to their doom, thankfully, but all the same the legacy of our ancestry is written through the pages of our history. Homo sapiens is the end-product of an unsuccessful series of Ganymean genetic experiments!