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5. SURVIVAL-OF-THE-FITTEST |
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Biological
evolution presumably functions by mutation, genetic drift, migration and
natural selection. Natural
selection is supposed to operate through differential reproduction or
“survival-of-the-fittest." Is
“survival-of-the-fittest" a rational basis for the concept of
biological evolution? This
question can be answered “no” with certainty. Consider the following two theses:
The
principle encompassed by the phrase
“survival-of-the-fittest" can be expressed by the
biconditional statement "A if and only if B."
In
such a statement, A and B may be different ways of stating exactly the
same idea. If so, the
sentence “A if and only if B" is a type of tautology -- it is always true.
Conversely, if A and B express different ideas then the statement
"A if and only if B" is regarded as false when either A is
true and B is false or B is true and A is false. If
the particular sentence with which this chapter is concerned is viewed
as a tautology, then it is just as devoid of scientific content as the
sentence “a man is married if and only if the man is a husband." If A and B express different ideas, then
circumstances must be found such that the truth of A and the truth of B
can be independently tested before the truth of the biconditional can
be evaluated. Herein lies
the problem. The truth of
“creature is most fit" cannot be tested for any
creature under any circumstances because the overall “fitness" of
the creature can neither be measured nor computed.
Since the truth of A is untestable, it follows that the truth of
“A if and only if B" is likewise untestable.
Therefore, the answer to the question addressed in this chapter
is “no." Although
deficiencies fatal to the theory of biochemical evolution are gradually
being recognized by the scientific community, our inability to measure
or compute the “fitness" of a creature has not yet been viewed as
fatal to the theory of biological evolution.
Investigators generally settle for measuring small numbers of
morphological, physiological or behavioral “traits" and insinuate
that, if all other aspects of “fitness" are fixed, these traits
alone will suffice. Unfortunately,
no theory is available which shows how the vast majority of aspects may
be fixed while a chosen few are free to vary.
A change in a single trait may alter 1000 aspects important to
the overall “fitness” of an organism.
What sort of interfering parameters might exist cannot even be
imagined due to the absence of a theory for reducing the organism to a
calculable whole. If the concept of natural selection is clearly untestable, why does the theory of biological evolution continue to dominate the field of biology? Partly because the concept's untestability makes it immune to falsification. Partly because the concept has become integrated into the common working knowledge of the biological community and has become the context within which that community understands the world. Partly because the alternative appears to involve God. (10) |
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