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