Evolution: Facts, Fallacies, and Crisis
(Copyright 1997 by Lloyd Eby)
One of the major problems in any discussion of evolution is
that the term "evolution" is used in a number of different ways -
- it is a quite plastic notion. Some of these usages are not
controversial, but others are very much so. Proponents of
evolution frequently make the mistake of taking evidence for one
of these usages as evidence for a quite different one, thus
committing a logical error or fallacy. (The reader can judge
whether this is done innocently or with malice.)
There are, I think, at least eight different notions or
claims or statements that are frequently subsumed under the
heading of "evolution," as follows:
What is Evolution?
Group-A:
1. The earth and living things on it are much older than 6000
years. (This means that the so-called "young earth theory" -
- held by a few religious fundamentalists or Biblical
literalists -- is denied.)
2. Living species did not appear on earth all at once. (This
claim can be further stated or specified as:)
2A. Changes in biological organisms have occurred over time.
2B. Change in allele frequencies occurs.
3. Mutation (in DNA, or whatever other form may be specified)
occurs in living things.
4. Natural selection occurs. (This is sometimes described in
terms of "evolutionary advantage.")
5. 3 + 4 together (i.e., mutation + natural selection, in
whatever way these may be understood) are the cause of *some*
(but not all) changes in biological organisms.
Group-B:
6. 3 + 4 together (i.e., mutation + natural selection) can
account for *all* changes in biological organisms (i.e., can
account for all speciation and the coming into being of all
biological differences and biological structures, after the
first living cell appears).
7. 3 + 4 together (i.e., mutation + natural selection) are the
only possible (or intellectually credible) account for all
changes in biological organisms.
8. Metaphysical naturalism must be accepted as the only (possible
or intellectually credible) stance. (As opposed to
metaphysical supernaturalism or theism.)
There does exist, I think, overwhelming and conclusive
evidence -- geological, palentological, biological, etc. --
supporting the truth of each of the statements 1 through 5. In
other words, we are warranted in saying that statements 1 through
5 are true. *If evolution is defined as claiming that any or all
of the statements 1 through 5 are true, but only that,* then we
can say that evolution is conclusively shown to be true. Thus, if
the claim "evolution is true" means *only* that one or more of
the statements 1 through 5 is asserted to be true, then that
claim "evolution is true" is warranted or true.
Here, however, is the most important point: The truth of any
of the statements 1 through 5 -- or of all the statements 1
through 5 taken together -- does *not* yield the truth of *any*
of the statements 6 through 8.
The truth of 1 through 5 does offer *some* evidence toward
the truth of 6 through 8, but does not prove them; in fact it
comes nowhere near proving them. In other words, it is perfectly
possible, logically and otherwise, for all of 1 through 5 to be
true and for all of 6 through 8 to be false.
Personally, I think that each of the statements 1 through 5
is, in fact, true and that each of the statements 6 through 8 is,
in fact, false.
The error in much evolutionist thinking and argumentation comes
about, I think, because of this confusion: 1 through 5 are known
to be true. Moreover the truth of 1 through 5 offers some
evidence toward the truth of one or more of the statements 6
through 8. On that basis, many evolutionists go on to assert that
one or more of the statements 6 through 8 is true.
This is, I think, an error that occurs in all -- or nearly all --
allegedly scientific accounts of evolution: a subtle or not so subtle
slide back and forth from group-A claims (statements 1 through 5) to
group-B ones (statements 6 through 8).
Statements 1 through 6 are scientific claims. Statements 7
and 8 are metaphysical -- extra-scientific -- ones. Genuine
science is (or should be, I think) restricted to non-metaphysical
claims. Metaphysical claims go beyond science into an extra-
scientific domain: the realm of philosophy of science.
One of the greatest offenders that I know of in this arena
is Richard Dawkins's book *The Blind Watchmaker*, which I regard
as being about the worst book I've ever read. Dawkins gives
sufficient evidence to justify the claim that 1 through 5 are all
true. No reasonable person who is at all familiar with the
evidence should deny the truth of any of those 5 claims. (Dawkins
also asserts gradualism, as opposed to saltationism or punctuated
equilibrium, and offers evidence and arguments -- poor evidence
and inconclusive arguments, in my opinion -- for it. But although
the debate between gradualism and anti-gradualism is crucial to
discussions of evolution, it is outside the scope of what I think
I need to consider for my purposes here.) On the basis of the
truth of 1 through 5, Dawkins then goes on to assert the truth of
6 and then 7 *without giving anywhere near sufficient evidence
for their truth* -- instead he gives a lot of hand-waving and "it
must have been's" and "we can only suppose's" and so on -- what
are frequently called (by others) "just-so stories." Moreover, he
adopts a pugnacious and polemical style and stance -- a lack of
modesty and of the scientific spirit of tentativeness -- to cover
his logical and metaphysical errors.
*The Blind Watchmaker* is not really, I think, a book of
science, but instead is one of metaphysical assertion (especially
atheism, or atheology) masquerading as science. Dawkins is more
committed to his atheism than he is to sound logic or good
science, and this dictates his argumentation and his supposedly
scientific investigation. As you can tell from my tone here,
Dawkins irritates and offends me immensely; I regard *The Blind
Watchmaker* as being not just factually or logically wrong, but
evil.
There are, however, several further issues that severely
complicate things.
First, what is usually called modern science -- that is the
empirical science of today that goes back at least to Copernicus
-- has been successful because it has adopted statement 8 (the
stance of metaphysical naturalism) as its methodological stance.
In other words it has assumed that all observable phenomena or
data can be investigated and that this investigation must be done
in naturalistic terms -- i.e., it has held that there must be a
naturalistic explanation (as opposed to a supernatural one) for
everything. We have methods for testing naturalistic hypotheses,
but we do not really have methods for testing extra-naturalistic
or supernaturalistic ones. Another way of making this point is to
say that, for modern science, to be scientific has meant to be
naturalistic, and modern science has made enormous discoveries
and advances through and because of that stance.
In reply to that we can say that there is no adequate reason
why metaphysical naturalism must be the only truly scientific
stance. But, in practice, this stance has yielded all the results
and explanations of modern science, and it seems reasonable to
suppose that had this naturalistic stance not been taken then all
the advances and discoveries we think of as modern science would
not have come about. Moreover, although there may be ways of
testing extra-naturalistic hypotheses, we have not, in fact,
possessed them in any way that we could really call scientific.
The question of whether extra-naturalistic hypotheses and
explanations can be tested in any adequate way thus remains open
and unanswered, I think. Another way of saying this is that we do
not at this time have available any good or adequate model or
paradigm for a non-naturalistic science.
A second problem is that statements 6 and 7 (in whatever way
they are understood, i.e., in whatever way the most recent or
most subtle or most adequate form of evolutionism as a stance or
ideology is understood to be defined or to operate) do give a
paradigm (to use Thomas Kuhn's terminology) and a research
program (to use the terminology of Imre Lakatos and others) for
the biological sciences. Thus, the denial of 6 or 7 would leave
the biological sciences (as they presently exist, anyway)
foundering, at least to an important extent. For that reason,
those biologists who hold to the notion of evolution embodied in
those statements 6 or 7 frequently challenge anti-evolutionists
to propose some other testable theory if they wish to deny the
evolutionary one.
From one point of view that demand is reasonable -- having
no alternative theory but nevertheless denying the evolutionary
stance or paradigm would seem to leave the biological sciences
without any way of going ahead. From another point of view,
however, that demand for an alternative need not be met by the
anti-evolutionist. One can know or be convinced that an
explanation or theory is false or inadequate without needing to
propose an alternative. (For example, I can know that it is false
that John murdered Mary without knowing who did, in fact, kill
Mary or even without having any good theory about how Mary died.)
So, the burden is not necessarily on the anti-evolutionist to
propose another theory, but one can understand why evolutionists
frequently become exasperated with anti-evolutionists. It is
difficult for any science to admit that it is stymied in its
present theoretical base and its research program, and that it
does not yet know how to get beyond that impasse. (I mean this to
be both a psychological and a logical-methodological
observation.)
Thus, at present, we are left with an impasse between
evolutionists and anti-evolutionists, even though the anti-
evolutionists have the better argument. I think that a crisis now
exists in the biological sciences and that a paradigm shift -- as
Thomas Kuhn understood crisis and resulting paradigm shift -- is
needed as a way out of the crisis.
- Lloyd Eby