The year is 1995. The place
is an imaginary after-world from which all aspects of life on earth
can be monitored. A gigantic party is underway with all the famous thinkers
of history in attendance. Socrates, who is a little more boisterous
than usual, weaves his way among the guests, calling out, "Darwin!
... Darwin! ... Where is that man?!" Eventually Darwin hears his
name being called and answers:
D Socrates! Over here!
S Oh, there you are. Look,
I've got to have a talk with
you. The matter is serious.
I have been following the development of evolutionary thinking for over
one hundred and thirty-five years and after listening to the experts
I still cannot make head or tail of it.
D What is your problem?
S Well, first of all, I
simply do not know what people mean
when they say things like
"man evolved" or "because of evolution this or that happened."
Now I realize that today even the earthly school children can say the
word "evolution" with an air of confidence and understanding.
And I also see that the word appears in all manner of magazines and
popular books on biology. But do these people really understand what
they confidently talk about? I mean, it is possible to fit a supposedly
technical word into an informal conversational sentence without making
a grammatical mistake, and still not have a fig of a notion as to what
one means by it. It seems to me that nothing but the vaguest of ideas
is being traded in all this talk about evolution.
D You ought to realize,
Socrates, that scientific words have a way of slipping their moorings
in the technical disciplines and drifting into the mainstream of everyday
conversation. And when they do, not everyone who uses these words has
a clear understanding of their meanings. Practically every discipline
suffers because untrained people use its jargon vacuously, usually because
they want to impress their friends. But for every one hundred people
who mindlessly parrot a scientific term like "evolution" there
is probably at least one person who can explain its meaning. Also, you
must not assume that because a technical term comes tripping off the
tongues of individual discussants in a conversation they do not know
what the word means. It would be very awkward indeed if a person always
had to explain the underlying concepts of such terms in order to speak
intelligibly. It is precisely because some words stand for a whole cluster
of concepts that they find their usefulness as shorthand notation in
S Well said, Darwin! You
are just the man to explain this whole business to me. Please tell me
then what evolution is.
D You suggested that you
are familiar with the literature.
Surely you do not want me
to start with the basics.
S Yes, I do. Be as simple
as you can without sacrificing the truth, because I must have missed
something at a very rudimentary level.
D The word "evolution"
simply means "change"; and the scientific theory of evolution
is the theory which states that organisms have gradually changed from
the most simple forms into the most complex forms, beginning with unicellular
organisms and ending with man; at least ending for the time being. This
gradual change took place during the course of millions of years and
its basis in fact has been established by the observations of science.
The best way to ...
S But do not scientists
today speak of evolution as a fact?
You say it is a theory.
Which is it?
D Yes, you can say that
it is a fact. The theory is based upon observed facts and ...
S But is the process of
change itself observable? I mean that change to which, presumably, the
word "evolution" refers.
D Yes! Now will you please
stop interrupting and let me continue?
S I'm sorry. Please continue.
D As I started to say, perhaps
the best way to see this
change is by examining some
of the more important explanatory parts of the theory. First, the structural
explanations of the theory of evolution explain the similarities of
body structure found among organisms of widely diverse species living
today. For example, although the whale, the bat, the horse and man are
members of quite diverse species, their appendages exhibit marked similarities.
The flipper of the whale, the wing of the bat, the leg of the horse,
and the arm of man are all structurally alike, even though they are
functionally different. Evolution explains the presence of these structural
similarities by pointing out that the organisms of these diverse species
have an ancestor or ancestors in common from which they have descended.
Over many years of descent from a common ancestry these different organisms
have changed; though not enough to erase the structural similarity we
still observe today. Descent, with change, from a common ancestry also
accounts for the presence of vestiges in many different organisms. You
must have read that vestiges are remnants of larger and once useful
body parts; organs, appendages, etc. which have atrophied through lack
of use as the whole body of the organism descended and changed. For
some reason these original parts did not disappear completely, although
their functional contribution to the organism disappeared. The vermiform
appendix in man and the wings of flightless birds are two familiar examples
S All of this sounds disturbingly
familiar. You see it is this business about descent and change that
bothers me. I asked you what evolution is; you said that it is the change
of organisms from one form into another. Further, you said that this
change can be seen by looking at the structural similarities between
members of diverse species, which presumably illustrate the change in
question. But since I have only the vaguest notion as to what this process
of change is like, it is hardly enlightening to point to the perceived
structural similarity between organisms and to their vestigial organs
as evidence of this change. In other words, the idea of descent with
change is what I am asking you to explain; but you have presupposed
it with your reference to similar structures and vestigial organs. Unless
I have missed something, this looks like a subtle species of question
D Look, the evidence is
as clear as the nose on your face. How else can we account for these
similarities between life forms? Why should these organisms exhibit
a similar structure unless in fact they had descended from a common
S I can't see the nose on
my face very well and neither can I see very well this vaguely conceived
change you speak of. If you are going to start asking "why"
questions at the very general level of structural similarities between
organisms can you not exercise your imagination and think of something
which has greater conceptual definition than "descent, with change,
from a common ancestry?" Of course, I do not know the answer to
this biological riddle, but I can think of at least one theory which
will account for such similarities. Perhaps the god which sent me on
my philosophical mission to the people of Athens devised a good plan
by which to make the species of his creation function well. He may have
used the same basic structural design in many diverse species, much
the same as automobile manufacturers today on earth retain the same
basic design for different models. The same design, with modification,
can serve many purposes. Just as you asked your "why" question,
so I can ask mine. "Why should a creator throw away a perfectly
useful basic design?"
D You can't be serious!
That is a preposterous notion. The scientific community generally rejects
such antiquated thought.
S That may be a true statement
about what most scientists believe, but you are not suggesting that
truth in science is established by counting the beliefs of scientists,
D Even if I were so backward
as to entertain the possibility of such a creation, your theory still
would not work. Just because similarities between the structural designs
of automobiles can be accounted for in terms of a modification of the
ideas of the inventor or manufacturer, it does not necessarily follow
that the structural similarities between organisms can be accounted
for in the same way by referring to a creator of living organisms. Change
in complexity and in apparent design can be accounted for in more than
S True enough, but this
establishes my point. Just as it does not follow necessarily that the
developmental changes in automobiles and the developmental changes in
organisms are the result of essentially the same kind of process, neither
does it follow necessarily that those changes are not the result of
the same kind of process. They both could be the result of creative
planning. And at this level of observation, where you seem to see evidence
of evolutionary change I merely point out that there is a good alternative
way of explaining the same perceived phenomenon of structural similarity.
But more importantly, my idea of creation gives an intelligible account
of what the change is and how it is to be conceived: namely, a creative
change in the basic plan of the god. Your notion, however, still lacks
definition; it presupposes that some kind of change occurred within
nature and among different organisms. You have yet to conceptually identify
for me what this change is which presumably is at the heart of evolutionary
D You might be able to conceive
of possible alternatives to evolution but you cannot dismiss the facts
which evidence evolutionary change.
S But that is precisely
the point of contention. What is factual is not changing, at least not
to the degree needed to transform one species into another. All the
organisms which you claim have descended from a common ancestry; the
whale, the bat, the horse and man; have not changed into different species
throughout the thousands of generations of their observed existence.
Furthermore, any of the organisms which you may imagine to have been
their ancestors and which are still living today; some of the reptiles,
for example; also have not changed throughout successive generations
of their offspring. The change which is supposed to distinguish evolution
as an important scientific fact is precisely what is lacking when we
examine it. And speaking of the facts, as your disciples today are wont
to do, the evidence you adduce in support of this vaguely conceived
notion of change is highly suspect. In reference to your own example,
I have noticed over the years that as the knowledge of animal physiology
has increased, the number of vestigial organs so-called has dwindled
drastically. Earlier in the history of evolutionary theory some biologists
writing on the topic listed more than one hundred and eighty of these
rudimentary structures. The human body alone became a veritable museum
of evolutionary remnants. But today I see that most textbooks which
treat the subject at all list only about six vestigial organs, with
of course the vermiform appendix in man still being given the most prominent
place. Unfortunately, the category of "chief vestigial organ"
has itself become vestigial; because immunologists now do not think
that the appendix is a useless remnant. The role of the appendix in
human immunology is well established.
D So, what are you ultimately
saying Socrates: that with a few examples like those you can overturn
the scientific theory of evolution? I suppose the next thing you will
tell me is that the entire fossil record is also not a fact! What do
you propose we do with the countless fossils laid down in the strata
of the earth's crust in such a fashion that only the most obtuse observer
could fail to get their message?
S I have always been slow
to understand popular concepts. Will you please tell me what that unmistakable
message is that you get from the earth?
D Come now, my friend! You
must know that fossils have been laid down in the earth's strata in
a clearly discernible pattern. The pattern I refer to; as I think you
already know; is the gradual and progressive change in complexity of
the life forms which have been fossilized. Beginning with very simple
organisms fossilized in the Cambrian layers, you can see, as you move
up through successive layers, a graduated complexity in the forms of
life, until you reach the most complex organisms in the most recent
layers at the top. The unmistakable message is that simple organisms
have progressively changed or evolved into highly complex organisms.
S You asked me what I proposed
to do with the fossil record. I do not propose to do anything with it
except seriously try to give it the most sensible interpretation, and
I must say that your interpretation does not strike me as the most sensible
one. Your traditional account of the fossil record manifests the same
weaknesses as your so-called structural explanations. First, the alleged
facts upon which you construct your theory of evolutionary progression;
whatever that is precisely; are not nearly so factual once you look
carefully at them. Second, given an account of the facts as they really
are, there is a better alternative explanation than evolution: as I
said, a creative change in the basic plan of the god.
You claim that the fossils
evidence a gradual progressive change in the complexity of life forms,
beginning with simple organisms in the bottom layers and ending with
complex organisms in the top layers. But unfortunately the evidence
cannot be made to conform to such a simple account. In actual fact the
change one observes is neither gradual, nor progressive, nor does it
begin with simple organisms.
Whatever you wish to say
about those life forms at the bottom of the evolutionary ladder, organisms
such as sponges and protozoa, you ought not to say that they are simple.
Contrary to public opinion the story of evolution does not begin with
simple organisms, but with very complex ones. Even single-celled organisms
exhibit a degree of complexity which is awe-inspiring. It seems to me
that accounting for the composition, structure and sophisticated functions
of such allegedly primitive organisms is a major problem for the theory
of evolution. As well, among the oldest fossils one can find evidence
of prehistoric animals which seem to have been at least as complex as
modern animals; perhaps more so. Therefore, because the organisms whose
remains are found in the deepest strata are not "simple" in
any ordinary sense of the term, and because the remains of highly complex
animals are found where they should not be found if evolution is true,
it is a misrepresentation of the facts to simply say that the change
which fossils exhibit begins with simple organisms or that it always
progresses from simple organisms to complex ones.
But worse still, the changes
from one organism to another which the fossils are supposed to exhibit
cannot consistently be called gradual. Within many important sections
of the geological column where you find a succession of fossils, from
less complex in the bottom layers to more complex in the top layers,
the succession is not gradual! At many junctures within these sections
there are tremendously large jumps in the complexity of organisms, with
no trace of a series of graduated intermediate forms to account for
the alleged evolutionary change. Doesn't evolution here become a kind
of "god of the gaps?" Where, for example, are all the intermediate
forms between birds and reptiles? I can see no way that such leaps in
complexity can be accounted for by a theory which relies so heavily
upon the "long - long - ago - over - a - long - long - time"
theme in its scenario. Even one hundred million years of sedimentary
deposition cannot begin to account for the colossal jumps in the complexity
of these life forms. Is evolution consistent with its own canons? Don't
you see ...
D Now hold on just a minute!
You talk so simplistically, as though evolutionary development were
a simple linear progression laid out like beads on a string. You will
do much better if you think of it as a progression, using the model
of a tree. Granted, several of the branches are missing, which we shall
probably be able to draw in some day, but the main outline is there.
Evolution has been a very complex process which we do not completely
understand, but I am confident that eventually we shall understand it
and thereby clear up the major problems that remain.
S I wondered when you were
going to use that old ploy. You appeal to scientific ignorance of the
workings of this allegedly complex evolutionary process, but at the
same time assert the existence of that process by emphasizing its inscrutability;
when all the while the very existence of the process itself is precisely
what is in question! It is in question because there is neither a clear
referent for the phrase "evolutionary change" nor unambiguous
evidence to support the evolutionary ideas of change even supposing
the referent for "change" were clearly given. How is it that
although you do not have the requisite fossil evidence to support evolutionary
theory you still know that evolution occurred? And how does its occurrence
gain existential status in the deep recess of your ignorance? My response
to your claim that there is so much about the workings of evolution
that we don't understand, is: how do you know that it is evolution that
has been working?
D Obviously because we can
see clearly the broad outlines of its work.
S You are still begging
the question. The vital evidence you need to support the claim that
it is evolution's work which is broadly outlined, and not the work of
some other force, is missing. Do you not see that by the same kind of
reasoning you could say that a few different colored dots on a canvas
are, without further evidence, the broad outlines of a Rembrandt? There
is no disanalogy here because, contrary to popular belief, it is not
in fact the case that just a few branches are missing from the tree
of evolution; whole sections of the main trunk are missing! The onus
is not upon me to see how much I can exercise my imagination by filling
the blanks; the onus is upon you to provide evidence which will support
such an imaginative theory. It is your responsibility to produce the
important missing pieces: not mine to trail after your flights of imagination.
D Socrates, I now think
I see your problem. You fail to make a distinction between the results
of evolutionary change and the process of change itself. Obviously we
cannot observe the change which modified all those species in the past;
but we can infer the existence of such a change from the fossil remains.
S Be careful now. You are
wandering in a circle. We have already discussed the gappy fossil record.
Let us not wander back to the fossil remains and what we are supposed
to be able to infer from them; for we have seen large problems along
that path. You seem not to be grasping the main point of my criticism.
When you say "results of evolutionary change," notice: you
assume that the "change" has taken place; when in fact it
is precisely this change that I am asking you to substantiate. What
you desire to call the "results" of change I have argued are
really the deficient beginnings of your case for evolution. Logically
you cannot call these weak beginnings "the results." Furthermore,
it is not only that the fossil record is lacking in evidence; it presents
contradictory evidence. Not only are many fossils missing which should
be present; there are many fossils present where they should be missing.
Let me illustrate the point.
Suppose that an earthling walks into his dining room in the morning
and sees a beautiful vase on a table. Later that afternoon he returns
to the dining room, but this time he sees the vase smashed in pieces
on the floor. There has been a change all right, but the "how"
of that change may not at all be clear. Was it the cat, an earth tremor,
a human hand, gravity, the wind, or something else? Unless he has more
evidence than just the memory of the unbroken vase in the morning, together
with the spectacle of smashed pieces in the afternoon, it is presumptuous
of him to single out any one of those agents as being responsible for
the destruction. Notice, however, that he can bridge the gap between
his remembrance of the vase intact and his perception of the broken
pieces before him, by using his imagination. But if all that he uses
to bridge the gap is his imagination, then the change which he proposes;
for example, the movement of the cat's tail against the vase; is merely
a conceptual change, with no basis in fact. He needs more than a jumping
imagination to account for change in the world around him.
The need for evidence of
a specific kind of change is much more acute in the case of evolution;
because there you want to argue not only that a change took place in
nature itself, but that simpler organisms changed into more complex
organisms, by chance. Unlike the change in the vase, the notion of evolutionary
change is counter-intuitive; it is especially important to fill in the
gaps with something more than the imagination.
I am not denying, for example,
that reptiles are different from mammals. And there is of course a conceptual
change which one must make in moving from his thoughts about fossils
of reptiles to his thoughts about fossils of mammals. But unless one
has something more to offer than the catch phrase "because of evolutionary
change," his ideas remain groundless. The "how" of evolutionary
change is not, as many scientists seem to think, a non-essential extra
to be filled in at some later date. It is the very heart of this putative
process. If the "how" of evolutionary theory cannot be identified
and coherently described, and if clear non-contradictory evidence at
the crucial points cannot be given in support of the theory, then, to
speak of "evolutionary change" as a distinctive occurrence
within nature is to speak vacuously.
D You keep harping on this
business of change, as though evolution had been discovered yesterday.
You said that you have been reading the literature. Have you not read
anything about natural selection and genetic variation?
S Yes, I have - and you
would have done as well if you had read Mendel instead of leaving him
alone on your library shelf - he is, after all, the father of your theory,
is he not? But never mind, like the rest of evolutionary theory, I cannot
make head or tail of natural selection and genetic variation. Now, I
will stop harping if you change your tune.
D Speaking of "old
ploys," that one of playing the dummy is wearing rather thin. I
remember your tricks. Let me guess: now you want me to give you a basic
lesson in the mechanics of evolutionary change?
S Yes indeed I do! And let
me assure you that my ignorance is not feigned; I really do not understand
all this business. That is why I have come to you, the expert.
D Well, when I first conceived
of the theory of evolution I accepted the Lamarckian assumption that
hereditary changes are produced by the environment. In order to adapt
to a particular environmental niche for which it was not viably suited,
an organism acquired the characteristics necessary for survival. The
environment, so to speak, urged upon the organism the acquisition of
these characteristics; or, so we thought. In addition, I also thought
that, corresponding to this change in the organism;'s characteristics,
hereditary changes were somehow produced, such that the newly acquired
characteristics could be transmitted to succeeding generations. All
of this of course was before the advent of genetics. It is now believed
by those who still accept my basic evolutionary model that the mechanisms
of change are different. Neo-Darwinians hold that hereditary changes
are the result of gene mutations. Simply stated, instead of saying that
the environment produces adaptive changes which are hereditary, it is
now said that hereditary changes make adaptation possible. Changes in
the genetic makeup of an organism alter that organism in such a manner
as to prepare it for an environmental niche into which it can emigrate.
This genetic preparation is sometimes called preadaptation. Let me give
you a simple illustration. It is often discovered that the inhabitants
of caves are blind and possess highly developed tactile sense organs.
According to my old view, the darkness forced the would-be cave inhabitants
to give up using their eyes and acquire an acute sense of touch. The
revised Neo-Darwinian view says that this is putting the cart before
the horse. Actually, the would-be inhabitants must be equipped to survive
before they emigrate to the caves. That is, they are preadapted by a
genetic mutation which results in a heightened tactile sensitivity.
S Please forgive another
simple-minded question, but why would anyone think in the first place
that organisms adapt to their environments, either in the manner you
first proposed or in the manner proposed by your followers today?
D Well, obviously, because
of the compatibility which exists between organisms and their environments.
It must surely be evident even to your critical mind how well organisms
and their environments fit together: the environment being suitable
to accommodate the organism and the organism being fit to exist in its
environment. This harmonious state of affairs can be observed everywhere
S But have these adaptations
of new organisms to new environments ever been observed? I do not mean
just those changes in parts of an organism such as tails getting longer
or fur changing color, etc., as a result of cross-breeding within the
same species. These confined changes were observed and well known to
everyone hundreds of years before the word "evolution" gained
any currency. I mean, has anyone ever scientifically observed a radical
change in an organism at the specific or even sub-specific level, such
that the radically new organism could fit into a radically new environment?
Or, has anyone even observed an organism like the bat losing its sight,
then gaining a heightened sense of touch and hearing, and then emigrating
to a radically new environment like a cave where it continued to live
and reproduce offspring similarly adapted?
D Of course not. Natural
selection at the level you are asking about cannot be directly observed.
It is a very complex process which has taken a great deal of time.
S But would you not agree
that adaptation at that level has got to be established before evolution
may be called an explanatory scientific theory about how organisms have
D Certainly the changes
must have been radical but the ...
S Well, if small changes
such as the variations in the size
of an appendage, or in the
color of some body part, cannot provide the evidence needed for the
appearance of these radically new organisms, upon what basis do you
argue that such large scale changes have occurred which enable an organisms
to adapt to a radically new environment?
D I have already told you:
upon the basis of the harmonious interaction of organisms with their
environment. The organisms must have changed dramatically in order to
fit into new environmental niches.
S Let me understand what
you are saying. You say that organisms and their environments fit together?
D Yes, that's right.
S And they fit together
because the organism adapts to its
S And when I ask you how
you know that the organism does
adapt to a radically new
environment you say, because the organism and its environment fit together.
D Yes, that's my position.
S Don't you see that you're
arguing in a circle? You jump
from the observed harmony
in nature to the mysterious conclusion that organisms change dramatically
and then adapt to a radically new environment, providing no other factual
support for this grand inductive inference than the obvious facts about
harmony with which you started. It seems that evolutionists use the
notion of "fitness" both as a starting observation and as
a concluding explanation. The only facts involved in your case for natural
selection are those which are obvious and agreeable to everyone before
any inferences are drawn. As a description of the way organisms and
their environments are suited to one another, part of your account is
unobjectionable; but as a putative explanation of how organisms have
come into being, natural selection really does not provide an answer.
At best we may learn how some existing organisms survive a radical environmental
change; such as black moths in sooty trees; but not how they radically
change in surviving. I repeat my former criticism of putative "evolutionary
change": the change that you need to demonstrate is precisely what
you assume throughout your whole account. And, if you are going to take
such liberty with inductive inference you should not object to an alternative
inference of no greater breadth which is drawn from the same observations
about natural harmony. Why not infer that the delicate balance of nature
everywhere observed is the work of a god who ...
D You might have gotten
away with that kind of argument in your time, or even one hundred years
ago, but not now. I think that I have already made it plain that the
idea of genetic variation forms an integral part of evolutionary theory
as it is taught today. No one any longer speaks about natural selection
without saying or implying that genetic variations form an integral
part of the evolutionary process.
S Well then, are you now
admitting that the main support for the belief in evolutionary change
is found in genetics? I should soon very much like to get to the foundation
of this whole matter.
D Yes, you could say that.
The evidence for change you so eagerly seek is found in the fact of
S But is there really any
scientific evidence; I mean solid data; not fanciful theorizing; which
shows that a mutant form of an organism can change it into anything
like what is needed to reproduce a new species?
D Come now, you must surely
have read about the mutant forms in plants, animals, and insects. Are
you not familiar with the fruitfly experiments? Countless mutants of
the Drosophila have been observed and written up in the literature.
S It seems that you are
not the only one who thinks he is not being heard. I have just asked
a question the thrust of which you seem to be completely ignoring. The
weakness of the genetic explanation for evolution lies precisely in
the alleged evidence you advance in support of it. Even if the highly
improbable occurred, that is, even if a thousand of such mutants occurred
in one and the same fruitfly, you would still not have an organism whose
total change represented anything like a new species actually found
in nature. And what is important here of course is that such a large
scale change never has been observed.
D I do not know what literature
you have been reading, but a mutation which can change an antenna into
a leg is quite a powerful piece of evidence for the mechanism of evolutionary
S That is a very misleading
description my friend. What you are suggesting is the origination of
a new complex structure, a leg, is really just the switching of an already
genetically encoded structure to a new location, the place of the antenna,
where it then develops. What is worse, however, is that this sort of
aberrant switching is disadvantageous to the fly, even if, hypothetically
speaking, one could say that some new genetic material were being added
to the blueprint of the fly, which definitely is not the case. If you
are going to gain any distance with the genetic argument you will have
to show that an organism can create new genetic material which increases
radically the complexity of the structure or function of the organism,
thus enabling it to adapt to a radically new environment. If, for instance,
we have evolved from protozoa, where did the genes for a nervous system,
bones, etc. come from? There is a huge gap here which needs to be filled.
D Even so, the small genetic
changes that we do observe provide us with a good working idea of how
large scale changes in organisms could have occurred and thus produced
radically new organisms.
S Has anyone ever observed
these grand genetic changes which you imagine could have been the impetus
for evolutionary advancement?
D No, of course not, but
just because they have not been observed, it does not mean that they
did not occur! You have not shown that such changes could not have happened.
S No it does not; but neither
does it mean that they did occur. But, since you are the one advancing
the theory, the onus is yours to establish its truth. It is not my responsibility
to satisfy your impossible request, to show that some imagined events,
such as large scale genetic changes which, as purely imagined events,
are not logically impossible, could not occur. That kind of demonstration
cannot be provided in any world, let along be provided in evolutionary
theory. Nor is it ever a reasonable request that it should be provided.
How, for example, would you ever demonstrate that a creator could not
possibly exist? You must base your case for evolution on positive available
evidence; unless of course you decide to give your ideas, as they now
stand, a more suitable title: "a poetic vision" or "a
secular faith" or something similar. I am afraid that you have
not yet felt how heavy the burden of proof is which rests upon your
D And you seem to have something
against speculation in science. In fact, you misrepresent the scientific
process. Listen, it would be ridiculous for scientists to formulate
only theories for which there was already confirming evidence. Surely
it is not necessary to present the confirming evidence for possible
advantageous macromutations before I theorize that they have occurred?
S I have nothing at all
against speculation, in science or anywhere else. I only wish that you;
and especially your followers; would call it exactly that, instead of
making grandiose claims about the evidence for evolution. You give everybody
the impression that evolution is firmly grounded on facts. You claim
that genetics has the answer to the questions of change which I have
just been pursuing. And yet when the truth is told, either, the changes
which can actually be observed are small, not radical, and most often
disadvantageous to an organism, thus providing no relevant evidence
for the large scale changes required by evolution; or, the changes are
large but non-existent, purely products of your imagination, having
no basis in fact. So, in either case the foundational support for the
claim that evolution has occurred has yet to be established.
D I grant you that the theory
may have some weaknesses in each of its various explanatory parts, but
when the explanations are taken altogether, I think you will have to
admit, they present a very convincing account.
S That's like saying that
although one leaky bucket will not hold water, ten leaky buckets will.
D It depends on how far
you want to carry the water!
S Yes, and how big the holes
are! But to carry the
of life forms all the way from noncellular organisms to man? That is
a very long way, my friend. You began by discussing structural similarities
and vestigial organs. When I pointed out that your account not only
contained factual mistakes but also presumed without justification the
answer to my basic question of evolutionary change, you directed our
discussion to the fossil record and the supposedly unmistakable pattern
which is exhibited there. When I pointed out further factual errors
and emphasized again your persistence in assuming without warrant the
very change in question, you then led us into a discussion of what are
apparently the dual pillars of evolutionary theory, natural selection
and genetic variation. And now after I have once again pointed out that
even in the genetic account radical change is being assumed, not evidenced,
you still want to go back over this whole business and say that somehow
all the missing supports for your theory are able to make it stand.
Is not that an odd kind of argument?
D How else can we account
for the existence of complex life forms?
S Goodness gracious! You
are surely not suggesting that a bad theory is better than none at all?
Has it never occurred to you to say, "I do not know"? You
ought to read Wittgenstein.
D But no intellectually
respectable scientist today could doubt it!
S That is the problem with
you people. You hold your theories with such religious fervour that
you cannot detach yourself from them long enough to ask a few basic
D And the problem with philosophers
is that they are always preoccupied with semantics. Clever word play,
S I have never pretended
that philosophy is anything but the art of asking uncomfortable questions
about fundamental assumptions. Say what you like against philosophers,
but that will not remove the serious criticisms which hound your theory.
D Do you realize what you're
suggesting? Are you asking me to believe that all of these venerable
men of science are misguided because they do not have any clear idea
of evolutionary change? One should not dignify the suggestion with a
S I do not know this, but
let me tell you what I think is the main reason for the perpetuation
of this conceptual confusion. The pseudo-explanatory force of evolutionary
theory derives its psychological power from the fact that anthropomorphic
terms within its narrative are readily understood in non-scientific
D What in thunder does that
S Consider the fanciful
character of the stories that are
spun around the fossil remains.
We read about vertebrates who left their aquatic environment and developed
limbs by a happy accident. And with their newly developed limbs these
amphibians learned to linger about the drying pools. In the story of
the descent from the trees we read of men-like, tree-borne primates
who became earth-borne creatures. They assumed an erect posture, lengthened
and strengthened their lower limbs; and the latter became organs of
the mind. A more anthropomorphic story would be difficult to write.
It is hardly a step at all to imagine a group of turtles getting together
for a conference to make plans for an exploring expedition. Of course
if these action verbs and nouns are read anthropomorphically then the
conclusion towards which the evolutionary argument moves is assumed
at the outset. Presumably the lower forms of life somehow developed
into the complex form called man. Therefore, in the beginning they did
not possess, even at the amphibian stage, the motivation and ability
to direct their destinies, as man is able to do. To smuggle into the
language of explanation the suggestion that they did is to gain a psychological
support for the central thesis of evolution which needs to be established
legitimately by non-semantical means.
story of evolution is conceived so generally that it can accommodate
almost any idea, which in fact it does. Not only does it deposit in
its store the scientific jargon of "fossils," "strata,"
etc., but it also incorporates with ease the anthropomorphic language
of epic poetry. The scientist learns to speak in one breath of "carbon
dating," "developing limbs" and "happy accidents."
His narrative explanation admixes science and saga, with a strong emphasis
upon the latter. And the anthropomorphic action terms find ready acceptance
in the minds of readers because their minds are accustomed to using
such terms daily in ordinary sensible contexts. For example, "the
development of limbs" is thought to convey something intelligible
because "the development of muscles" or "the development
of talent" are perfectly sensible.
It is this practice of semantical
borrowing which makes popular books on evolution so saleable. People
see beautifully colored charts and read in the captions below all about
the saga of evolution. Even the children can repeat with confidence
the story of "amphibians developing limbs" and "reptiles
taking to flight." And all of this is done with an air of clear
understanding, as if evolution were really being explained.
D Socrates, I am afraid
that you have now stepped out onto a very long limb from which, sadly,
there is no return. Don't you realize that no scientist in his senses
would claim that these narrative accounts explain how evolution occurred?
They serve merely as an heuristic device, thats all.
S Are you saying that these
accounts are used only for teaching purposes and are not intended as
explanations of the evolutionary process?
D Yes, that's right.
S That leads me to ask two
questions. If the narratives
are meant to be taken only
as a kind of grand mnemonic, then ought not the writers of these accounts
say so unequivocally, to make clear the metaphorical nature of their
language? For it certainly seems that they intend for the narratives
to be taken as explanations. My second question, however, leads me to
doubt your easy interpretation of these narratives. In order for the
story of evolution to represent the truth it must surely be based upon
a knowledge of the mechanisms for evolutionary development; otherwise
there is no guarantee that the story corresponds to the actual developmental
process which it merely wants to picture. But if that is the case, what
are these known mechanisms of progressive radical change in the development
D Natural selection and
genetic variation, of course!
S But you're arguing in
a circle again. We have already
seen that there is nothing
in genetics which can account for the radical changes required by your
theory. And now you want to base the epic, "protozoa to man,"
on this foundationless support.
You know, Darwin, the longer
I talk with you the more questions I have. Could it be that the theory
of evolution is not only a question-begging argument, but something
even more problematic? Is it even empirically significant? I mean to
ask, does the key phrase "evolutionary change" have an empirical
If one tries to discover
how evolution works he is told that the causal factors involved are
not observable, not repeatable, not simple, and not agreeable to all
scientists. And if one wants to see this negative qualification on a
grand scale he need only look at the history of the subject. When Lamarckism
and Darwinism failed, evolution succeeded. When Vitalism and Finalism
failed, evolution still succeeded. Even though Neo-Lamarckians and
Neo-Darwinians have been at loggerheads about crucial matters, evolution
supposedly stands above the confusion and contradictions. What is
this change called "evolution" which survives all the vicissitudes
of its vague and contradictory explanations? How does this alleged process,
which cannot be repeated or observed or even specified, and whose supporting
explanations of natural selection and genetic variation crumble beneath
the weight of logical-empirical analysis, differ from no process at
D Enough! I do not want
to hear any more of this nonsense.
What you are saying is silly!
Socrates calmly turned and
walked away, and as he cleared a path among the guests he was heard
muttering to himself, "I wonder if Freud is here. Perhaps he can
help me understand what Darwin said."
 "A theory may be
described as 'vitalistic' if it purports to give a systematic explanation
of evolution in terms of some unique non-natural agency" such as
"the 'life force', 'elan vital', entelechy, etc." (Goudge,
"Just as vitalism is
not necessarily finalistic, so finalism is not necessarily vitalistic.
For the core of finalism is the contention that a necessary condition
of evolution consists of its orientation towards an ultimate goal."
The goal may be reached by "mechanically determined processes."
(Goudge, p. 81)
 Neo-Lamarkism holds
"...that the effects of use and disuse [of parts of an organism],
together with other environmentally induced changes, can become fixed
in the hereditary equipment of species..." (Goudge, pp. 85,86)
Neo-Darwinism, simply stated,
is Darwinism without the Lamarkian assumption that hereditary changes
are produced by the environment, and with the assumption that heredity
changes stem from genetic variation in the organism. A complete account
would be much more complicated than this and would reveal that Neo-Darwinians
differ significantly in their evolutionary views according to the theory
of mechanism for genetic variation and natural selection which they
This dialogue descended
from an unpublished paper of 57 pages written long ago, titled "The
Language, Truth and Logic of Evolutionary Theory." That paper in
turn derived some of its nourishment from the following works.
Bonner, J.T. 1961. Perspectives.
American Scientist 49:240-244.
Davidheiser, B. 1969. Evolution
and Christian Faith. The Presbyterian and Reformed Publishing Co.,
Nutley, New Jersey.
Dewey, J. 1951. The influence
of Darwinism on philosophy. In Classic American Philosophers,
edited by Max H. Fisch. Appleton-Century-Crofts Inc., New York, pp.
Dobzhansky, T. 1958. Evolution
at work. Science 127:1091-1098.
Flew, A. 1955. Theology
and falsification. In _New Essays in Philosophical Theology_, edited
by A. Flew and A. Macintyre. SCM Press, London, pp. 96-99.
Goldschmidt, R.B. 1952.
Evolution, as viewed by one geneticist.
Goudge, T.A. 1961. The
Ascent of Life. University of Toronto Press, Toronto.
Maatman, R.W. 1970. The
Bible, Natural Science and Evolution.
Reformed Fellowship, Inc.,
Moore, J.N. and R.J. Cuffey.
Paleontologic evidence and organic evolution. Journal of the American
Scientific Affiliation 24:160-176.
Simpson, G.G. 1949. The
Meaning of Evolution. Yale University Press, New Haven.
Wittgenstein, L. 1972. Lectures
and conversations on aesthetics, psychology and religious belief, edited
by C. Barrett, University of California Press, Berkeley.
Disclaimer and Acknowledgement
Over the past dozen years
or so we have seen published a spate of books which challenge Neo-Darwinism.
Authors who come to mind are P.E. Johnson, D. Davis and D.H. Kenyon.
Spirited defenses of Neo-Darwinism have been mounted by many authors,
two of the most prominent of them being S.J. Gould and M. Ruse. Neither
in writing this dialogue nor in revising it have I borrowed from these
more recent authors, its main thesis having been written well before
the relevant works of these authors appeared.
I must, however, thank Jon
Buell for reading the unrevised dialogue and making several helpful
suggestions for its improvement.