places?”
Danchekker shook his head and smiled almost benevolently.
“We are scientists, not mystics,” he replied. “One of the funda
mental principles of scientific method is that new and speculative
hypotheses do not warrant consideration as long as the facts that
are observed are adequately accounted for by the theories that
already exist. Nothing resembling a universal guiding force has
ever been revealed by generations of investigation, and since the
facts observed are adequately explained by the accepted principles
I have outlined, there is no necessity to invoke or invent
additional causes. Notions of guiding forces and grand designs
exist only in the mind of the misguided observer, not in the facts
he observes.”
“But suppose it turns out that Charlie came from somewhere else,”
the metallurgist insisted. “What then?”
“Ah! Now, that would be an entirely different matter. If it should
be proved by some other means that Charlie did indeed evolve
somewhere else, then we would be forced to accept that parallel
evolution had occurred as an observed and unquestionable fact.
Since this could not be explained within the framework of
contemporary theory, our theories would be shown to be woefully
inadequate. That would be the time to speculate on additional
influences. Then, perhaps, your universal guiding force might find
a rightful place. To entertain such concepts at this stage,
however, would be to put the cart fairly and squarely before the
horse. In so doing, we would be guilty of a breach of one of the
most fundamental of scientific principles.”
Somebody else tried to push the professor from a different angle.
“How about convergent lines rather than parallel lines? Maybe the
selection principles work in such a way that different lines of
development converge toward the same optimum end product. In other
words, although they start out in different directions, they will
both eventually hit on the same, best final design. Like . . .” He
sought for an analogy. “Like sharks are fish and dolphins are
mammals. They both came from different origins but ended up hitting
on the same general shape.”
Danchekker again shook his head firmly. “Forget the idea of
perfection and best end products,” he said. “You are unwittingly
falling into this trap of assuming a grand design again. The human
form is not nearly as perfect as you perhaps imagine. Nature does
not produce best solutions-it will try any solution. The only test
applied is that it be good enough to survive and reproduce itself.
Far more species have proved unsuccessful and become extinct
than have survived-far, far more. It is easy to contemplate a kind
of preordained striving toward something perfect when this
fundamental fact is overlooked-when looking back dawn the tree, as
it were, with the benefit of hindsight from our particular
successful branch and forgetting the countless other branches that
got nowhere.
“No, forget this idea of perfection. The developments we see in the
natural world are simply cases of something good enough to do the
job. Usually, many conceivable alternatives would be as good, and
some better.
“Take as an example the cusp pattern on the first lower molar tooth
of man. It is made up of a group of five main cusps with a complex
of intervening grooves and ridges that help to grind up food. There
is no reason to suppose that this particular pattern is any more
efficient than any one of many more that might be considered. This
particular pattern, however, first occurred as a mutation somewhere
along the ancestral line leading toward man and has been passed on
ever since. The same pattern is also found on the teeth of the
great apes, indicating that we both inherited it from some early
common ancestor where it happened through pure chance.
“Charlie has human cusp patterns on all his teeth.
“Many of our adaptations are far from perfect. The arrangement of
internal organs leaves much to be desired, owing to our inheriting
a system originally developed to suit a horizontal and not an
upright posture. In our respiratory system, for example, we find
that the wastes and dirt that accumulate in the throat and nasal
regions drain inside and not outside, as happened originally, a