“Quite right,” Hunt confirmed. “All it proved was that a planet existed. It didn’t prove that the Lunarians evolved on it. As you say, there was still the problem of parallel evolution.” He ificked his cigar at the ashtray and shook his head with a sigh. “All kinds of theories were in circulation. Some talked about a civilization from the distant past that had colonized Minerva and had some
how gotten cut off from home; others said they had evolved there from scratch by some kind of convergent process that wasn’t properly understood. . . . Life was becoming crazy.”
“But at that point we encountered an extraordinary piece of luck,” Danchekker came in. “Your colleagues from Jupiter Four discovered the Ganymean spaceship-here, on Ganymede. Once the cargo was identified as terrestrial animals from about twenty-five million years ago, an explanation suggested itself that could account adequately for the whole situation. The conclusion was incredible, but it fitted.”
Shannon nodded vigorously, indicating that this answer had confirmed what he had already suspected.
“Yes, it had to be the animals,” he said. “That’s what I thought. Until you established that the ancestors of the Lunarians had been shipped from Earth to Minerva by the Ganymeans, you had no way of connecting the Lunarians with Minerva. Right?”
“Almost, but not quite,” Hunt replied. “We’d already managed to connect the Lunarians with Minerva-in other words we knew they’d been involved with the planet somehow-but we couldn’t account for how they could have evolved there. You’re right, though, in saying that the animals that the Ganymeans shipped there long before solved that one in the end. But first we had to connect the Ganymeans with Minerva. At first, you see, all we knew was that one of their ships conked out on Ganymede. No way of knowing where it came from.”
“Of course. That’s right. There wouldn’t have been anything to indicate that the Ganymeans had anything to do with Minerva, would there? So what finally pointed you in the right direction?”
“Another stroke of luck, I must confess,” Danchekker said. “Some perfectly preserved fish were found among the food stocks in the remains of a devastated Lunarian base on Luna. We succeeded in proving that the fish were native to Minerva and had been brought to Luna by the Lunarians. Furthermore, the fish were shown to be anatomically related to Ganymean skeletons. This, of course, implied that the Ganymeans too must have evolved from the same evolutionary line as the fish. Since the fish were from Minerva, the Ganymeans also had to be from Minerva.”
“So that was where the ship must have come from,” Hunt pointed out.
“And where the animals must have come from,” Danchekker added.
“And the only way they could have got there is if the Ganymeans took them there,” Hunt finished.
Shannon reflected on these propositions for a while. “Yes.
I see,” he said finally. “It all makes sense. And the rest everybody knows. Two isolated populations of terrestrial animals resulted- the one that had always existed on Earth, and the one established on Minerva by the Ganymeans, which included advanced primates. During the twenty-five million years that followed, the Lunarians evolved from them, on Minerva, and that’s how they came to be human in form.” Shannon stubbed his cigar, then placed his hands flat on the table and looked up at the two scientists. “And the Ganymeans,” he said. “What happened to them? They vanished completely twenty-five million years back. Are you people anywhere near answering that one yet? How about leaking a little bit of information in advance? I’m interested.”
Danchekker made an empty-handed gesture.
“Believe me, I would like nothing better than to be able to comply. But honestly, we haven’t made any great strides in that direction yet. What you say is correct; not only the Ganymeans, but also all the land-dwelling forms of life native to Minerva died out or disappeared in a very short space of time, relatively speaking, at about that time. The imported terrestrial species flourished in their place and eventually the Lunarians emerged.” The professor showed his palms again. “What happened to the Ganymeans and why? That remains a mystery. Oh. . . we have theories, or should I say we can offer possible explanations. The most popular seems to be that an increase in atmospheric toxins, particularly carbon dioxide, proved lethal to the natives but not to the immigrant types. But to be truthful, the evidence is far from conclusive. I was talking to your molecular biologists here on 15 only yesterday; some of their more recent work makes me less confident in that theory than I was two or three months ago.”