'The problem with Charlie, and the rest of the Lunarians, that has not been touched upon is this: quite simply, they were too human.'
Puzzled looks appeared here and there. Somebody turned to his neighbor and shrugged. They all looked back at Danchekker in silence.
'Let us recapitulate for a moment some of the fundamental principles of evolution,' he said. 'How do different animal species arise? Well, we know that variations of a given species arise from mutations caused by various agencies. It follows from elementary genetics that in a freely mixing and interbreeding population, any new characteristic will tend to be diluted, and will disappear within relatively few generations. However'-the professor’s tone became deadly serious-'when sections of the population become reproductively isolated from one another-for example, by geegraphical separation, by segregation of behavior patterns, or by seasonal differences, say, in mating times-dilution through interbreeding will be prevented. When a new characteristic appears within an isolated group, it will be confined to and reinforced within that group; thus, generation by generation, the group will diverge from the other group or groups from which it has been isolated. Finally a new species will establish itself. This principle is fundamental to the whole idea of evolution: Given isolation, divergence will occur. The origins of all species on Earth can be traced back to the existence at some time of some mechanism or other of isolation between variations within a single species. The animal life peculiar to Australia and South America, for instance, demonstrates how rapidly divergence takes effect even when isolation has existed only for a short time.
'Now we seem to be satisfied that for the best part of twenty-five million years, two groups of terrestrial animals-one on Earth, the other on Minerva-were left to evolve in complete isolation. As a scientist who accepts fully the validity of the principle I have just outlined, I have no hesitation in saying that divergence between these two groups must have taken place. That, of course, applies equally to the primate lines that were represented on both planets.'
He stopped and stood looking from one to the other of his colleagues, giving them time to think and waiting for a reaction. The reaction came from the far end of the room.
'Yes, now I see what you’re saying,' somebody said. 'But why speculate? What’s the point in saying they should have diverged, when it’s clear that they didn’t?'
Danchekker beamed and showed his teeth. 'What makes you say they didn’t?' he challenged.
The questioner raised his arms in appeal. 'What my two eyes tell me-I can see they didn’t.'
'What do you see?'
'I see humans. I see Lunarians. They’re the same. So, they didn’t diverge.'
'Didn’t they?' Danchekker’s voice cut the air like a whiplash. 'Or are you making the same unconscious assumption that everyone else has made? Let me go over the facts once again, purely from an objective point of view. I’ll simply list the things we observe and make no assumptions, conscious or otherwise, about how they fit in with what we think we already know.
'First: The two populations were isolated. Fact.
'Second: Today, twenty-five million years later, we observe two sets of individuals, ourselves and the Lunarians. Fact.
'Third: We and the Lunarians are identical. Fact.
'Now, if we accept the principle that divergence must have occurred, what must we conclude? Ask yourselves- If confronted by those facts and nothing else, what would any scientist deduce?'
Danchekker stood facing them, pursing his lips and rocking back and forth on his heels. Silence enveloped the room, broken after a few seconds by his whistling quietly and tunelessly to himself.
'Christ…!' The exclamation came from Hunt. He stood gaping at the professor in undisguised disbelief. 'They couldn’t have been isolated from each other,' he managed at last in a slow, halting voice. 'They must both be from the same…' The words trailed away.
Danchekker nodded with evident satisfaction. 'Vic’s seen what I am saying,' he informed the group. 'You see, the only logical conclusion that can be drawn from the statements I have just enumerated is this: If two identical forms are observed today, they must both come from the same isolated group. In other words, if two lines were isolated and branched apart, both forms must lie on the same branch!'
'How can you say that, Chris?' someone insisted. 'We know they came from different branches.'
'What do you know?' Danchekker whispered.
'Well, I know that the Lunarians came from the branch that was isolated on Minerva…'
'Agreed.'
'… And I know that man comes from the branch that was isolated on Earth.'
'How?'
The question echoed sharply around the walls like a pistol shot.
'Well,' The speaker made a gesture of helplessness. 'How do I answer a question like that? It… it’s obvious.'
'Precisely!' Danchekker showed his teeth again. 'You assume it-just as everybody else does! That’s part of the conditioning you’ve grown up with. It has been assumed all through the history of the human race, and naturally so-there has never been any reason to suppose otherwise.' Danchekker straightened up and regarded the room with an unblinking stare. 'Now perhaps you see the point of all this. I am stating that, on the evidence we have just examined, the human race did not evolve on Earth at all. It evolved on Minerva!'
'Oh, Chris, really…'
'This is getting ridiculous..
Danchekker hammered on relentlessly: 'Because, if we accept that divergence must have occurred, then both we and the Lunarians must have evolved in the same place, and we already know that they evolved on Minerva!'
A murmur of excitement mixed with protest ran around the room.
'I am stating that Charlie is not just a distantly related cousin of man-he is our direct ancestor!' Danchekker did not wait for comment but pressed on in the same insistent tone: 'And I believe that I can give you an explanation of our own origins which is fully consistent with these deductions.' An abrupt silence fell upon the room. Danchekker regarded his colleagues for a few seconds. When he spoke again, his voice had fallen to a calmer and more objective note.
'From Charlie’s account of his last days, we know that some Lunarians were left alive on the Moon after the fighting died down. Charlie himself was one of them. He did not survive for long, but we can guess that there were others-desperate groups such as the ones he described-scattered across that Lunar surface. Many would have perished in the meteorite storm on Farside, but some, like Charlie’s group, were on Nearside when Minerva exploded and were spared the worst of the bombardment. Even a long time later, when the Moon finally stabilized in orbit around Earth, a handful of survivors remained who gazed up at the new world that hung in their sky. Presumably some of their ships were still usable-perhaps just one, or two, or a few. There was only one way out. Their world had ceased to exist, so they took the only path open to them and set off on a last, desperate attempt to reach the surface of Earth. There could be no way back-there was no place to go back to.
'So we must conclude that their attempt succeeded. Precisely what events followed their emergence out into the savagery of the Ice Age we will probably never know for sure. But we can guess that for generations they hung on the very edge of extinction. Their knowledge and skills would have been lost. Gradually they reverted to barbarism, and for forty thousand years were lost in the midst of the general struggle for survival. But survive they did. Not only did they survive, they consolidated, spread, and flourished. Today their descendants dominate the Earth just as they dominated Minerva-you, I, and the rest of the human race.'
A long silence ensued before anybody spoke. When somebody did, the tone was solemn. 'Chris, assuming for now that everything was like you’ve said, a point still bothers me: If we and the Lunarians both came from the Minervan line, what happened to the other line? Where did the branch that was developing on Earth go?'
'Good question.' Danchekker nodded approval. 'We know from the fossil record on Earth that during the period that came after the visits of the Ganymeans several developments in the general human direction took place. We can trace this record quite clearly right up to the time in question, fifty thousand years ago. By that time the most advanced stage reached on Earth was that represented by Neanderthal man. Now, the Neanderthals have always been something of a riddle. They were hardy, tough, and superior in intelligence to anything prior to them or coexisting with them. They seemed well adapted to survive the competition of the Ice Age and should, one would think, have attained a dominant position in the era that was to follow. But that did not happen. Strangely, almost
