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29+ Evidences for Macroevolution
A Response to Ashby Camp's "Critique"
Copyright © 1999-2003 by Douglas Theobald,
Ashby Camp has penned a critique of these "29 Evidences of
Macroevolution," which can be found posted at TrueOrigin. Camp's critique is
well-written, very thorough, and quite lengthy (the criticism is longer than the
original article). Although I intend to address Camp's concerns in totality,
currently I can only devote a limited amount of time to this effort. In the
meantime, this partial response will suffice. I would like to thank Camp for his
congenial criticism. It has given me the impetus to rework and expand the "29
Evidences," and the result is a more comprehensive, clearer, and stronger
My response has been two-fold. First, I have incorporated new material into
the original essay that specifically addresses many of Camp's points, and thus
much of his response is now superfluous. Second, in the following sections I
rebut the more egregious errors found in Camp's criticism, especially ones that
would interrupt the flow and thrust of the original article if they were
included there. In the following response, Camp's words are indented in boxes, set apart from mine. Material that Camp has quoted
in his criticism is also in the boxes, surrounded
by quotes, and followed by the pertinent external reference.
Mr. Camp's critique is error-ridden in various ways, and is primarily
- Straw man arguments
- Red herrings
- Two wrongs make a right
- Fallacies of accident and converse accident
- Ignoratio elenchi
- Naive theological assumptions
- Insufficient knowledge of basic biology, molecular biology, biochemistry
- Misunderstanding of the scientific method
- Forwarding of untestable competing "hypotheses"
- Mischaracterization of evolutionary theory
- Misleading mis-quotes
- Fallacies of accent
- Distortion of scientific controversies
- Arguments from authority
- False analogies
The repeated use of these errors and others in Camp's "Critique" will be
abundantly clear in the following rebuttal.
Note: Since the time I wrote this reply, Mr. Camp has responded to
this in a shorter article entitled "Camp answers Theobald." The
elements which I felt deserve some mention are included here in bold.
Prediction 1: The fundamental unity of life
Ashby Camp writes:
The alleged prediction and fulfillment are:
- If universal common ancestry is true, then all organisms will have
one or more traits in common.
- All organisms have one or more traits in common.
Although Camp is most likely simply trying to paraphrase the point
succinctly, he distorts the intent in doing so. The prediction is more specific
than the above. To quote from the original prediction
"Some of the macroscopic properties that characterize all of life are (1)
replication, (2) information flow in continuity of kind, (3) catalysis, and
(4) energy utilization (metabolism) .... all living species today should
necessarily have ... inherited the structures that perform these
functions. The genealogical relatedness of all life predicts that organisms
should be very similar in the particular mechanisms and structures that
execute these basic life processes." (emphasis added)
Which traits should be in common was and is expressly stated -- the structures
and mechanisms that perform the four basic life functions.
Camp does not consider his paraphrase to be a straw man:
... I do not see how my summary phrasing qualifies as a straw man,
given that it encompasses the claim being made. If one argues that two
bullets must have come from the same gun because they have certain
striations in common, would it be a straw man to say the claim was that
the two bullets must have come from the same gun because they have one
or more traits in common? Specifying the traits (striations) does not
affect the nature of the argument ...
"Encompassing" a claim is not stating the claim, just as the United States is
not Colorado. Camp's gun-and-bullet example certainly is a straw man. We cannot
infer that two bullets came from the same gun if they have just any two traits
in common. For instance, two bullets might be both made of lead or they might
both weigh the same. Can we thus infer that they both came from the same gun?
No -- that inference is only valid when it is based upon traits that are caused by
a particular gun, such as specific striations. Rephrasing the argument as Camp
does is a straw
man, since the rephrased argument is a weaker form of the real argument, and
since the weaker form is much easier to criticize. Specifying the traits
certainly does change the nature of the argument, because the valid inference is
solely based upon certain types of traits (for bullets, those traits
caused by a specific gun; for common descent, those traits strongly constrained
Conflation of mechanism with gradualism
Unless one inserts an additional premise imposing a limit on the
degree to which descendants can vary (which would require specification
of a mechanism of descent), the claim of common ancestry does not
require that all of the descendants share one or more traits. There is
no logical reason why completely novel organisms could not arise
in one or more lineages. Absent specification of a mechanism of descent,
which Dr. Theobald purposefully avoids, there is no way to tether the
traits of the descendants to those of the common ancestor.
In fact, there are limits on the degree to which descendants can vary.
The constraint of gradualism is inherent in the theory of universal common
descent -- a point made explicitly in the original article. To quote from the
"... macroevolution is proposed to occur on a geological timescale and in a
gradual manner .... Gradualness concerns genetically probable organismic
changes between two consecutive generations, i.e. those changes that are
within the range of normal variation observed within modern populations."
Elsewhere in his criticism (e.g., footnote 6), Camp bemoans
the article's indifference to mechanism in explaining the evidence for common
descent. Throughout the article, it is assumed that the fundamentals of biology
(such as genetics, molecular biology, and developmental biology) are correct,
especially those not directly dealing with the origin and evolution of
biological adaptations. In creation-evolution debates this is not especially
controversial; nearly all anti-evolutionists, including those who believe in
special creation, also make this assumption. Though gradualism is not formally a
mechanism of evolution (like natural selection or Lamarckism could be),
gradualism does indeed put severe constraints on possible macroevolutionary
phenomena, and it also constrains any possible mechanisms. Thus, Camp is
incorrect when he says:
... universal common ancestry is compatible with all
mechanisms of common descent, including divine direction. So if God
chose to have a reptile give birth to a bird, for example, that would be
consistent with an "amechanistic" argument for universal common
A modern reptile giving birth to a modern bird is not gradual; it is
saltation, since such changes between two consecutive generations are not
genetically probable -- they are not "within the range of normal variation observed
within modern populations." This is not to say that God could not have created
species independently and miraculously, yet gradually. While there currently is
absolutely no scientific evidence for such an idea, gradual Divine
direction of evolution is indeed consistent and compatible with common descent.
In footnote 1, Camp
paradoxically criticizes the constraint of gradualism:
In restricting the mechanism of macroevolution to observable degrees
of genetic variation, Dr. Theobald lets in the back door the very debate
about mechanism that he tossed out the front. He thereby assumes the
burden of proving that accumulated observable variation can account for
universal common ancestry. Since he makes no attempt to meet that burden
but rather repeatedly disavows the relevance of any particular mechanism
of modification, I assume he did not intend to specify accumulated
observable variation as the mechanism of macroevolution, despite what
his definitions may suggest.
As stated earlier, though gradualism is not a mechanism, it does indeed
constrain possible explanatory mechanisms. Common descent is not concerned with
exactly how adaptive change has happened, but whether it has
happened and whether it is consistent with normal observed genealogical
processes. Camp is wrong to say that the sufficiency of "accumulated observable
variation" to account for universal common descent is left unaddressed. This
requirement was and is explicitly considered in Part 5, "Change and
Mutability," specifically in predictions 22, 23, 24, 28, and
A Misunderstanding of Evolutionary Fundamentals
Camp continues with ReMine's words:
"Second, even if life originated precisely once, then evolutionary
theory would still not predict biologic universals. Shortly after life's
origin, nothing prevented life from branching and leading separate
lineages to higher life forms entirely lacking the known biologic
Third, evolutionary loss and replacement processes could prevent
biologic universals. If one organism is a distant ancestor to another,
then nothing in evolution predicts the two must share similarities. If
evolution were true, then distant ancestors and descendants (as well as
sister groups) can be totally different." (ReMine
1993, p. 92-93)
Here Camp again dismisses the fundamentals of biology and the constraint of
gradualism. Common descent does predict specific biological universals,
since any significant change (any "loss and replacement processes") in the
structures that perform the four basic life functions would result in nonviable
organisms; these structures cannot be lost nor can they be replaced (although
they can be expounded upon). Once life attained these specific structures (by
whatever process), they were essentially frozen. Gradualism constrains life from
"branching and leading separate lineages to higher life forms entirely lacking
the known biologic universals." Of course "distant ancestors and descendants ...
can be totally different" -- totally different except in the structures that
perform the four fundamental functions of life.
Common descent does not predict that these structures must be identical, just
that the similarity must be statistically significant, and that there must be
viable intermediates between the variations. For instance, because the genetic
code is degenerate, common descent does not predict an identical genetic
code in all organisms. However, all known genetic codes are extremely similar,
with an extremely high degree of statistical significance. In fact, common
descent does not require that all organisms even have a genetic code. If life
evolved from something that lacked a genetic code, then there must have been a
series of organisms with transitional codes, beginning with no code at all. It
is at least possible that such organisms could still be alive today. But if
common descent is true, then the genetic codes of these organisms would be less
complex versions of the modern genetic code and would retain statistically
significant similarity to the modern universal genetic code. This is a testable
prediction, in principle.
That said, the main important point of "prediction 1" is this -- we can make
very strong a posteriori predictions about biological universals by
combining common descent with what is known. As a scientific analogy, Newton's
Theory of Universal Gravitation does not predict planets, nor does it predict
the present trajectories of planets. But given the known measured trajectory of
an existing planet, we can use Newton's theory to predict what the trajectory
will be in the future and what it must have been in the past, and these
predictions can be confirmed or falsified. Likewise, given the fact that we now
know that all organisms studied to date, including bacteria and birds, have a
very similar genetic code, we can use common descent to predict that all
undiscovered or unexamined organisms that fit between bacteria and birds in the
standard phylogenetic tree will also have a similar genetic code. Because of
common descent, we predict this even though this prediction is not functionally
necessary -- many other equivalent genetic codes could function equally well.
Because of common descent, we know that certain types of organisms will be
extremely similar in the biological universals before we actually go and check
the organisms to see what their structures really look like. Thus, Hunter is
incorrect when Camp quotes him saying:
"Consider how evolutionists would react if there were in fact
multiple codes in nature. What if plants, animals, and bacteria all had
different codes? Such a finding would not falsify evolution; rather, it
would be incorporated into the theory ... " (Hunter
2001, p. 38)
First, common descent does predict that the
genetic codes should be similar a priori. Hunter is speculating about how
biologists would have reacted in a hypothetical historical scenario in which we
did not find highly similar codes between organisms. In reality, we can never
know how biologists would have reacted to that, since that hypothetical scenario
did not happen. What is known, however, is that the scientists who
cracked the genetic code in the 1950's and 1960's worked under the assumption
that the code was universal or nearly so (Judson
1996, p. 280-281). These scientists, which included Francis Crick, Sydney
Brenner, George Gamow, and several others, all made this assumption and
justified it based upon evolutionary reasoning, even in the complete absence of
any experimental evidence. In fact, this assumption was instrumental in their
success in solving the code. For instance, in 1957, nearly ten years before the
genetic code was finally solved, Sydney Brenner published an influential paper
in which he concluded that all overlapping triplet codes were impossible if the
code was universal (Brenner
1957). This paper was widely considered a landmark work, since many
researchers were leaning towards an overlapping code. Of course, it turned out
that Brenner was correct about the nature of the true code. In 1961, five years
before the code was deciphered, Crick and others also concluded that the code
was (1) a triplet code, (2) non-overlapping, and (3) that the code is read from
a fixed starting point (i.e. the "start" codon) (Crick
et al. 1961). These conclusions were explicitly based on the
assumption that the code was essentially the same in tobacco, humans, and
bacteria, though there was no empirical support for this assumption. These
conclusions turned out to be correct. In fact, in 1963 -- three years before the
code was finally solved -- Hinegardner and Engelberg published a paper in
Science specifically explaining why the code must be universal (or nearly
so) if universal common descent were true, since most mutations in the code
would likely be lethal to all living things. Note, Hinegardner and Engelberg did
allow for some variation in the genetic code, and predicted how such variation
should be distributed if found:
"... if different codes do exist they should be associated with major
taxonomic groups such as phyla or kingdoms that have their roots far in the
and Engelberg 1963)
Their evolutionary prediction was correct, since the minor variations in the
standard genetic code are indeed associated with major taxonomic groups
(vertebrates vs. plants vs. single-celled ciliates, etc.).
Second, we now know from experimental research that many plants, many
animals, and many bacteria all have extremely similar genetic codes. There is no
known biological reason, aside from common descent, for why the genetic codes of
different species should be similar. Any new discovery of a plant, animal, or
bacteria with a radically different genetic code would be a highly unexpected
result if common descent is true.
Camp continues with Hunter's quote:
"There is nothing wrong with a theory that is comfortable with
different outcomes, but there is something wrong when one of those
outcomes is then claimed as supporting evidence. If a theory can predict
both A and not-A, then neither A nor not-A can be used as evidence for
the theory. When it comes to the genetic code, evolution can accommodate
a range of findings, but it cannot then use one of those findings as
supporting evidence." (Hunter
2001, p. 38.)
Common descent does not predict "both A and not-A" -- it predicts "both A and
B." Hunter equivocates by
misidentifying "A and not-A" with a range of predicted outcomes. A range
of outcomes (i.e. "A and B") does not necessarily encompass all possible
outcomes (i.e. "A and not-A") -- thus the equivocation. If a
theory predicts both A and B, then either A or B can be used as evidence
for the theory.
All scientific theories predict a range of outcomes. For example, Newtonian
physics predicts that projectiles will follow elliptical paths, parabolic paths,
or linear paths, contingent upon the relevant conditions. Newtonian physics thus
predicts A, B, and C, and any of A, B, or C can be used as evidence for
Newtonian physics. This point is important, since Camp uses this same argument
again, incorrectly, in his conclusion. Hunter's claim that "there is something
wrong when one of those [different] outcomes is then claimed as supporting
evidence" is clearly false as a blanket statement about scientific theories. To
rewrite Hunter's incorrect statement: when it comes to the genetic code,
evolution predicts a range of findings, and it can use any of those findings as
supporting evidence. That's how science works.
Camp further obfuscates the prediction of biological universals by
introducing hypotheses concerning the origin of the universal ancestor. He
The fact that some leading evolutionists believe early life forms
were biochemically distinct from modern forms confirms that evolution
does not predict biologic universals. Robert Shapiro, for example,
entertains the possibility of finding living relics of an original
protein-based life form that lacked DNA and RNA. (Shapiro, 293-295.)
Likewise, A. G. Cairns-Smith thinks that descendants of ancient
crystalline clay organisms may be all around us. He states: "Evolution
did not start with the organic molecules that have now become universal
to life: indeed I doubt whether the first organisms, even the first
evolved organisms, had any organic molecules in them at all."
First, exactly how the universal ancestor originated and evolved is not
within the realm of common descent; common descent concerns all evolution and
descent from the last common ancestor to the present. Secondly, and most
importantly, these speculative hypotheses have no influence upon certain
predictions of universals, such as the genetic code. The genetic code is a
mechanism to translate nucleic acid information (DNA and/or RNA) into protein.
Shapiro's original life form lacked DNA and RNA -- it did not have a genetic code.
Cairns-Smith's crystalline clay organisms had neither protein nor nucleic
acid -- thus neither did they have a genetic code. The universality of the genetic
code was proposed based upon two facts: all known life carries genetic
information in nucleic acids, and all known life performs metabolic functions
with proteins. All known life thus has a genetic code. If all known life is also
united by common descent, it must also be united by a universal genetic code. As
recounted above, this was the exact reasoning of Francis Crick, Sydney Brenner,
George Gamow, and Marshall Nirenberg when they were cracking the genetic code.
Camp, and other anti-evolutionists like ReMine, can carp and criticize -- yet the
fact remains that real biologists, doing hard science, made predictions and got
phenomenal results based upon common descent and the deduction of biological
On the other hand, ReMine argues that biologic universals are a
prediction of his message theory of creation, which "says all life was
constructed to look like the unified work of a single designer."
(ReMine, 94.) So evolution does not predict the unity of living things,
but at least one theory of creation does. Of course, the biochemical
similarity of living things fits easily within a creation framework.
Of course biochemical similarity fits easily in a "creation framework."
Anything can fit in the creation framework. This is precisely why present
anti-evolutionary creationist theories are unscientific; all possible results
are consistent with the "hypothesis." If there were no biochemical similarity,
would that be inconsistent with the "creation framework"? For example, if we
found an insect that had a genetic code radically different from the standard
genetic code, would that mean that Divine creation was impossible?
No -- creationists would not be scrambling to explain that result (but evolutionary
biologists would be).
ReMine's "message" hypothesis is much too vague to be tested scientifically.
What does a "unified work" look like? How would the biological world look if it
were a "divided work"? Can ReMine quantify "appearance of unity"? Would
independent researchers, perhaps from different cultures and countries, deduce
the same predictions from this "message hypothesis"? Surely not -- how something
"looks" in terms of unity is subjective; it is not an objective property of
life. How are we to distinguish between a single designer and multiple
designers? Does Microsoft Word or an iMac or a Nissan Pathfinder look like the
result of a single designer or multiple designers? A more fundamental problem is
that ReMine's "message" hypothesis is not mutually exclusive with common
descent, though he and Camp both seem to think that it is. Many world religions
consider the existence of physical laws, such as the theory of universal
gravitation, to be evidence that the universe is the unified work of a single
Designer. In principle, couldn't a single designer have used evolution to make
all of life look like a unified work? Of course; ReMine's conjecture and common
descent could both be true.
Naive Theology and Poor Biochemistry
Camp continues his discussion of how well he believes that creationism can
explain biochemical similarities by quoting this fine piece of "scientific"
creationist reasoning from Duane Gish:
"A creationist would also expect many biochemical similarities in all
living organisms. We all drink the same water, breathe the same air, and
eat the same food. Supposing, on the other hand, God had made plants
with a certain type of amino acids, sugars, purines, pyrimidines, etc.;
then made animals with a different type of amino acids, sugars, purines,
pyrimidines, etc.; and, finally, made man with a third type of amino
acids, sugars, etc. What could we eat? We couldn't eat plants; we
couldn't eat animals; all we could eat would be each other! Obviously,
that wouldn't work. All the key molecules in plants, animals, and man
had to be the same. The metabolism of plants, animals, and man, based on
the same biochemical principles, had to be similar, and therefore key
metabolic pathways would employ similar macromolecules, modified to fit
the particular internal environment of the organism or cell in which it
must function." (Gish, 277.)
Both Gish and Camp obviously feel that God is extremely limited in ingenuity.
Gish's contention is ridiculous; why couldn't God have created plants with one
certain type of amino acids and animals with another type, and simply given
animals the enzymes that metabolize plant amino acids? Wouldn't that be clever
design? Obviously, that would work, and all the key molecules in plants,
animals, and man did not have to be the same. Now, this fact does not mean that
God should have made things this way, but it certainly highlights the naive
theological assumption made by Gish and Camp that God was incapable of creating
things this way.
Another straw man
Camp ends his criticism of Prediction 1 with this straw man:
The claim that all organisms have one or more traits in common is
true in the sense that all living things necessarily have the traits by
which life is defined, but that is simply a tautology -- living things all
have the traits of living things.
As at the beginning, Camp's paraphrase is incorrect. The above claim is not
the prediction of biological universals; the prediction is that structures which
perform the basic functions that characterize life should be similar. Living
things have the functions of living things (a tautology), but because all things
are related by heredity (i.e. common descent), living things also should have
similar structures and mechanisms that perform these basic functions (a
deduction from common descent). It is possible that living things could all have
the basic functions that characterize life while also having very different,
chemically and structurally unrelated mechanisms that perform these basic
functions. The prediction of biological universals is, therefore, not
tautologous. And, as a deduction of common descent, the prediction of biological
universals is testable, confirmable, and falsifiable. Furthermore, this
prediction has been confirmed and has not been falsified. Like any good
scientific theory, the possibility exists that it may be falsified in the future
by the acquisition of new data, though this is highly unlikely since all other
evidence confirms the validity of common descent.
Prediction 2: A nested hierarchy of species
Misrepresentation of Evolutionary Theory and Erroneous Logic
Camp's argument is simply that descent by modification from a common ancestor
does not predict a nested hierarchy. Camp is just plain incorrect here; all
genealogical processes produce nested hierarchies. Think of your own family
tree -- your grandparents might have several kids, each of those kids (your aunts,
uncles, and parents) have their own families, each of the children in those
families (like you) may have their own children and even your children can have
their own families. Each family is nested within another family, which in turn
is nested within another family, and so on. Camp attempts to explain himself in
his refusal to accept this basic concept:
Common descent can explain or accommodate nested hierarchy ... but it
does not predict it. There are mechanisms of descent from a common
ancestor that would yield a different pattern. If common descent can
yield either nested hierarchy or something else, then the presence of
nested hierarchy does not count as evidence of common descent.
Camp claims that different patterns can result from common descent, but he
fails to provide any examples to support this odd claim. If Camp means that
"randomness" is a pattern (stretching the term "pattern"), then, yes, under
certain conditions common descent predicts that some characters of species will
be random with respect to each other. However, as has been discussed already,
all theories in science predict multiple outcomes contingent upon the relevant
conditions. This is not a problem for any scientific theory. Camp's last
statement above is transparently false; it is the same error discussed above in
Hunter's "A and not-A" claim. Common descent can predict two different outcomes
and it can still use either of those outcomes as supporting evidence.
Another Misunderstanding of Evolutionary Theory
Camp has since replied to this criticism:
... the claim that the hypothesis of universal common ancestry makes
a falsifiable prediction that organisms will exhibit a pattern of nested
hierarchy is incorrect. Indeed, Dr. Theobald acknowledged in both
prediction 2 and the response to my critique that Lamarck's organic
progression would yield a non-nested pattern of organisms. ... since
Lamarck's organic progression (to pick one example) admittedly does not
predict a nested hierarchy, a nested hierarchy is not evidence of common
descent via Lamarck's organic progression. Therefore, it is not evidence
of common descent regardless of "whether Darwinism, Lamarckism, or
something else is the true mechanism of evolutionary change," which is
the proposition being argued by Dr. Theobald.
Although Camp still does not provide us with an example of a non-nested
pattern generated by common descent, he does think that Lamarck's organic
progression would predict a non-nested pattern. Camp is correct. However, Camp
does not understand the difference between Lamarckism (or inheritance of
acquired characters), which is an evolutionary mechanism, and the Lamarckian
organic progression, which is not an evolutionary mechanism but is a descriptive
macroevolutionary theory. Of course Lamarck's organic progression does
not predict a nested hierarchy -- it is mutually exclusive with common descent.
Lamarck's organic progression is a competing theory, and common descent and the
organic progression cannot both be true. However, Lamarckian evolution (by
inheritance of acquired characters) could, in principle, be a mechanism of
change that drives common descent by gradual modification. Camp's discussion
here just proves my point. If we observed a pattern like that predicted by the
organic progression, it would strongly indicate that common descent was false
and that the organic progression was true. In other words, Lamarck's organic
progression predicts a non-nested pattern -- if we observed that pattern, it would
falsify common descent.
A Non-sequitor and Outdated Science
Camp then tries to support this misunderstanding with another quote from
|"It has been known since Aristotle that species tend to cluster in a
hierarchical pattern, and in the eighteenth century Linnaeus saw it as a
reflection of the Creator's divine plan. Obviously this pattern does not
force one to embrace evolution." (Hunter
2001, p. 107.) |
It seems clear to me that Hunter is implying that since the hierarchical
pattern of species was known before the theory of common descent was proposed,
then the hierarchical pattern cannot be used as evidence for common descent.
According to such logic, Newton's Theory of Gravity is also suspect. It has been
known since long before Aristotle that apples fall to the ground when dropped.
Some people before Newton, such as Aristotle, thought that apples were attracted
to the ground because they were primarily made of the "earth" element. Obviously
this pattern (falling) does not force one to embrace the inverse square law. It
should be clear that the fact that people were wrong about physical explanations
in the past is not an argument against modern scientific theories.
However, in private correspondence, Hunter has vociferously objected to my
interpretation of his comments given above. Hunter claims that he was simply
pointing out that alternative "theories" can explain the observed nested
hierarchy. For such a point to be valid, the alternate "theories" would need to
be of equal scientific rank as the theory of common descent. To my knowledge,
neither Aristotle nor Linnaeus proposed any hypothesis concerning the nested
hierarchy, and neither of them ever made any testable predictions based on any
hypothesis proposed to explain the nested hierarchy. In contrast, common descent
has certainly been proposed as a hypothesis which predicts the nested hierarchy,
and many predictions based upon universal common descent have been made and
tested by evolutionary biologists within the past 140 years. As such, the
philosophical and theological ideas of Aristotle and Linnaeus do not compete
scientifically with the formal hypothesis of common descent. Furthermore, there
is no reason why the theological significance Linnaeus attached to the nested
hierarchy should exclude common descent. It is possible for a theist to see the
theory of common descent, and the hierarchy which it predicts, as a reflection
of the Creator's divine plan -- much as Sir Isaac Newton saw his laws of motion,
and the ellipses and parabolas which they predict, as evidence of the Creator's
hand in our universe.
A Red Herring: 19th Century Science is Not Modern Science
Hunter's quote continues:
"Also, Darwin's law of natural selection does not predict this
pattern. He had to devise a special explanation -- his principle of
divergence -- to fit this striking pattern into his overall theory."
2001, p. 108.)
Branching or divergence of species (i.e. speciation) is an inherent part of
common descent. Darwin's principle of divergence of character was his
particular explanation for speciation, for how varieties eventually evolve to
become separate species. It was not "devised" as a "special explanation"; Darwin
cogently argued that it was a necessary result of natural selection.
"Natural selection, also, leads to divergence of character; for the more
organic beings diverge in structure, habits and constitution, by so much the
more can a large number be supported on the area, of which we see proof by
looking to the inhabitants of any small spot, and to the productions
naturalised in foreign lands. Therefore, during the modification of the
descendants of any one species, and during the incessant struggle of all
species to increase in numbers, the more diversified the descendants become,
the better will be their chance of success in the battle for life. Thus the
small differences distinguishing varieties of the same species, steadily tend
to increase, till they equal the greater differences between species of the
same genus, or even of distinct genera." (From the summary of Chapter 4,
Natural Selection, Darwin 1872, p. 169)
However, Darwin's specific principle is unnecessary for common descent to
produce a nested hierarchy -- all that is necessary is speciation and change in
characters, regardless of cause. Most importantly, the views of this 19th
century naturalist, though interesting historically, are of no consequence
whatsoever for the validity of modern evolutionary theories. Camp's insertion of
Darwin's views into a debate about modern science is a red herring (or a straw
man, either one). Camp has replied:
According to Dr. Theobald, Darwin's principle of divergence is simply
another name for ("is otherwise known as") common descent. The principle
of divergence was an addition to the bare notion of common descent that
"Darwin believed necessary to account for the diverging, tree-like
relationships of organisms" (quote from the Darwin Project at the
University of Cambridge, http://www.lib.cam.ac.uk/Departments/Darwin/intros/vol6.html).
As stated above, Darwin's "principle of divergence of character" is outdated
19th century science, not modern science, so the point is moot. That said, Camp
is incorrect and has misrepresented Darwin's thinking. The following discussion,
in italics, is solely for clarification of Darwin's views.
Darwin's principle of divergence was not "an addition to the bare
notion of common descent" -- if anything, it was an addition to the bare
notion of natural selection. In fact, Darwin saw the "principle of
divergence" as a deduction from natural selection acting on closely
related populations in different environments. As Darwin states in his
introduction to The Origin of Species,
"This fundamental subject of natural selection will be treated at
some length in the fourth chapter; and we shall then see how natural
selection almost inevitably causes much extinction of the less improved
forms of life, and leads to what I have called divergence of character."
1872, pp. 21-22)
"Natural selection, as has just been remarked, leads to divergence of
character and to much extinction of the less improved and intermediate
forms of life." (Darwin
1872, pp. 169-170)
"... it [the pattern of nested hierarchies] is explained through
inheritance and the complex action of natural selection, entailing
extinction and divergence of character, as we have seen illustrated in
the diagram." (Darwin
1872, p. 170)
It is possible to have common descent without natural selection, and it
is possible to have natural selection without common descent. Darwin's
principle tied the two together. As stated above, Darwin's "principle of
divergence of character" was his particular explanation for how natural
selection led to speciation, as Darwin wrote:
"Undoubtedly there is one most important point of difference between
varieties and species, namely, that the amount of difference between
varieties, when compared with each other or with their parent-species,
is much less than that between the species of the same genus. But when
we come to discuss the principle, as I call it, of divergence of
character, we shall see how this may be explained, and how the lesser
differences between varieties tend to increase into the greater
differences between species." (Darwin
1872, pp. 84-85)
In Chapter 4, Darwin formally introduces and explains his "principle of
divergence of character." There he clearly postulates it as a consequence
of natural selection working on similar populations in different
environments, thus leading to speciation. Darwin begins his section on the
principle of divergence with a question:
"The principle [of divergence] is of high importance, and explains,
as I believe, several important facts. In the first place, varieties,
even strongly-marked ones, though having somewhat of the character of
species [...] yet certainly differ far less from each other than do good
and distinct species. Nevertheless according to my view, varieties are
species in the process of formation, or are, as I have called them,
incipient species. How, then, does the lesser difference between
varieties become augmented into the greater difference between species?"
1872, p. 143)
Darwin answers this question with his principle of divergence, and he
explains how it can act in both domesticated and wild organisms. Then, he
uses his proposed concepts of (1) speciation by the principle of
divergence and (2) change by natural selection to demonstrate how a
branching tree-like genealogy of species will naturally develop:
"After the foregoing discussion [of the principle of divergence],
which has been much compressed, we may assume that the modified
descendants of any one species will succeed so much the better as they
become more diversified in structure, and are thus enabled to encroach
on places occupied by other beings. Now let us see how this principle of
benefit being derived from divergence of character, combined with the
principles of natural selection and of extinction, tends to act.
The accompanying diagram will aid us in understanding this rather
perplexing subject. ..." (Darwin
1872, p. 148-150)
Darwin then describes common descent using his famous
figure, the tree-like
phylogeny, which graphically represents the predicted nested
hierarchies. Note that the nested hierarchy is a consequence of only
speciation and change in character, which Darwin explained by use of the
principle of divergence and natural selection, respectively. From this
discussion it is clear that Camp is incorrect to state that the "principle
of divergence was an addition to the bare notion of common descent." The
principle of divergence was combined with evolution by natural selection
to deduce common descent with nested hierarchies. In fact, anytime
there is speciation, that is also common descent, so in a sense the
principle of divergence is common descent (though it is a special
case caused by the action of natural selection on different populations in
More Misrepresentation of Evolutionary Theory and Misunderstanding of the
Walter ReMine's Views of the Nested Hierarchy
Camp appears to be confused about whether common descent must include
branching of species or not:
Even a mechanism of descent that includes branching events does not
ensure a nested pattern.
If multiple species evolved from a common ancestor, how could they have
arisen without branching? "One" turning into "two" necessarily includes a
branching event. Divergence (i.e. speciation) is thus inherent in the
concept of common descent. Again, think about a family tree. Genealogies branch
and diverge. The very essence of common descent is that all species are related
like individuals in a genealogy.
Camp then quotes ReMine in support of his misunderstanding of the prediction
of nested hierarchies:
"The pattern of descent depends on the extent that evolved characters
are later lost. Suppose losses are significant, and characters are
replaced at a high rate. Then there is no reason to expect a nested
pattern. Descendants could be totally different from their distant
ancestors and sister groups, with little or no semblance of nested
similarities linking them." (ReMine, 343.)
ReMine is partially correct, yet errs large. If rates of evolution are fast,
then the cladistic information indeed can be lost given enough time, since the
cladistic information would be essentially randomized. The faster the rate, the
less time needed to obliterate the information in biological characters about
the historical branching pattern of evolution. Slowly evolving characters let us
see farther back into time; faster evolving characters restrict that view to
more recent events. This is a difficulty that biologists must deal with in
reality. But, importantly, it is also a prediction of common descent. Given a
certain rate of evolution, we can determine how long it will take for cladistic
information to be lost. ReMine forgets that "rate of evolution" vs. "time since
divergence" is relative; thus, in some time frame we will always be able to
observe a nested hierarchy if common descent is true. Furthermore, we know
empirically that background mutation rates vary by orders of magnitude from
locus to locus in the genomes of species. This fact means that hierarchies
should be observed at many biological levels, since some genes evolve faster or
slower than others.
ReMine thinks that since there are certain conditions under which a
prediction of our theory will not be observed, then observing the prediction is
not a confirmation of our theory. If this were true, we could never confirm any
scientific hypothesis, not just common descent, since there are always certain
conditions under which we will be unable to observe some consequence of a
All ReMine is saying is that, under certain conditions, common descent
predicts that hierarchical structure will be randomized. It is unclear why this
is a problematic feature of the theory of common descent. Under certain
conditions, Newtonian theory predicts that objects will not follow elliptical
orbits, but that they will follow parabolas. Are we thus supposed to conclude
that observing the elliptical orbits of the planets cannot be used as evidence
for Newtonian theory? No, and the same is true for common descent. This is the
same error as Hunter's "A and not-A" discussion addressed above. ReMine simply
does not understand how the scientific method works.
Camp has since contested my criticism of ReMine's arguments:
This is a mischaracterization of ReMine's position. ReMine is not
claiming that fulfillment of a theory's falsifiable prediction (e.g.,
the mutual attraction of two masses decreases in proportion to the
square of the distance between them) is nullified by an inability to
test the prediction under certain circumstances (e.g., where the
attraction is predictably below measurable limits).
The phrase "inability to test" is misstated. We can always test -- it is
only after testing that we compare the results to our predictions. Camp's
misstatement is just a further indication of an underlying misunderstanding and
unfamiliarity with scientific practice. If we assume that something is
untestable beforehand then we are assuming the truth of our theory -- we are not
testing it. How could we know that the attraction between two objects is
"predictably below measurable limits" unless we are already assuming that the
Theory of Gravity is true? We cannot; we must test that prediction and see if we
really are unable to measure the attraction when, using our theory, we predict
that the attraction should be too small to measure.
What Camp must mean here, to make sense, is "inability to observe a given
prediction" instead of "inability to test." In fact, this is exactly what
ReMine is claiming -- there is no mischaracterization. ReMine claims that
fulfillment of a theory's falsifiable prediction (e.g., the observation of a
"nested pattern") is nullified by an inability to observe the prediction under
certain circumstances (e.g., when the hierarchy is predictably randomized
because "losses are significant, and characters are replaced at a high rate").
As stated above, this claim is identical to Hunter's "A and not-A" equivocation.
Theories predict a range of outcomes; observing one of those outcomes and not
the others (contingent upon the relevant conditions) is still evidence for the
Rather, he [ReMine] is claiming that nested hierarchy is not a
falsifiable prediction of common ancestry because the theory includes
without restriction processes that work against that pattern. Those
processes can be invoked in any blend to account for any non-nested
pattern that is observed.
Well, ReMine is also making this claim. However, ReMine and Camp are
both incorrect in stating that it is problematic to invoke processes that "work
against" a prediction of a theory. For example, with Newton's Theory of Gravity,
there are plenty of things that can be invoked to account for anomalous results.
For instance, naively, feathers and bowling balls supposedly fall at the same
rate. If dropped from the same height, they should hit the ground at the same
time -- that is, if the theory is correct. But we all know that is untrue. Feathers
fall more slowly, and we invoke another process, air resistance, to explain why
feathers fall in a way not predicted by the theory. But there is more -- electrons
and protons do not follow the gravitational inverse square law either. We invoke
electric charge to explain that. Refrigerator magnets also "violate" the Theory
of Gravity. Here we invoke a process, magnetism, that works against the patterns
predicted by Newton's theory. In some cases, like three- or four-body problems,
we admit that Newton's theory fails to give an exact answer. When we are only
considering two objects, like the Sun and the earth, we can solve the equations
of motion exactly. But add just one more element, like the moon, and the
equations are impossible to solve (though the answers can sometimes be
approximated). In other cases, as with the orbit of Mercury, we drop Newton's
theory altogether and invoke relativistic effects.
In reality, all scientific explanations are complex, except in the
most unrealistic, contrived situations found in carefully controlled laboratory
environments. In a lab, we can remove the air from a container and watch a
bowling ball and a feather fall at the same rate. In contrast, we cannot
simplify things like that when we try to calculate the terminal velocity of a
falling body in our atmosphere. As stated elsewhere here, processes cannot "be
invoked in any blend to account for any [...] pattern." Complex explanations are
required to be reasonable and to conform to empirically observed processes -- they
are not invoked "without restriction." All the processes that ReMine and Camp
complain about have been empirically observed, and they are testable
propositions. Evolutionary biology, thus, is no more problematic than any other
scientific discipline. To repeat, ReMine simply does not understand how the
scientific method works.
Mr. Camp uses an additional quote from ReMine with the intent to criticize
common descent and the prediction of nested hierarchies:
"Evolution does not predict a hierarchical pattern. Simple processes
of loss, replacement, anagenesis, transposition, unmasking, or multiple
biogenesis would prohibit such a pattern. Since hierarchical patterns
(such as cladograms or phenograms) are not predicted by evolution they
are not evidence for evolution." (ReMine
1993, p. 444.)
However, Camp has misquoted ReMine. ReMine is not specifically referring to
common descent in this passage; he is writing about evolution in general.
ReMine keeps common descent and evolution distinct (as he should). For instance,
multiple biogenesis is not common descent. This is clear from the very next
sentence that follows the quote above:
"Life's hierarchical pattern (as displayed in cladograms and phenograms) is
too indirect to establish even the special case of common descent." (ReMine
1993, p. 444.)
ReMine considers common descent to be a special case of evolution, which of
course it is. But his point that common descent is not a necessary case
of evolution is senseless. It is analogous to criticizing the inverse square law
because it could have been an inverse cube law or an inverse factorial
law. He might as well say -- "Gravity does not predict elliptical orbits. Since
elliptical orbits are not predicted by gravity then it is not evidence for
gravity." Which he could have followed with -- "Elliptical orbits (as displayed by
planets and projectiles) are too indirect to establish even the special case of
the inverse square law." Despite ReMine's protestations, nested hierarchies are
measurable features of organisms -- their presence or absence can be quantified and
evaluated with statistics. The prediction of a nested hierarchy follows directly
from the hypothesis of common descent.
Furthermore, ReMine is incorrect in claiming that
"loss, replacement, anagenesis, transposition, unmasking, or multiple biogenesis
would prohibit" a hierarchical pattern. Of course, multiple biogenesis could,
but we are not considering multiple biogenesis, we are considering universal
common descent. The other processes mentioned all create hierarchical
patterns, since character losses, replacements, anagenetic changes,
transpositions, and reversals (unmasking events) are all inherited by
descendants of an ancestor. For example, if all apes are descendants from a
long-tailed primate common ancestor that lost its tail, then all apes will lack
tails, while other primates will have tails. If an ape acquired a gene by
transposition into the germ-line, then all descendants of that ape would inherit
that transposition. If some non-ape primate then had a short tail replace its
long tail, then all descendants of the short-tailed primate would inherit that
short tail. The result is a nested hierarchy.
| primates |
| ________________ _____________ ______________ |
| | apes | | long tails | | short tails | |
| | ______ ______ | | | | | |
| || no ||trans.|| | | | | |
| ||trans.|| || | | | | |
| | ______ ______ | _____________ ______________ |
| | | |
| ________________ |
These "simple processes" are the very types of things that make nested
Since this was written, Camp has replied:
There are various ways in which existing organisms could descend from
a common ancestor and not exhibit a nested hierarchy. Anagenesis, loss
of characters, replacement of characters, transposition of characters,
atavism (masking and unmasking), and convergence all work against a
hierarchical pattern, and the bare hypothesis of universal common
ancestry says nothing about the rate or prevalence of those processes.
They can be invoked in whatever blend is necessary to explain whatever
pattern is found. Therefore, the claim that the hypothesis of universal
common ancestry makes a falsifiable prediction that organisms will
exhibit a pattern of nested hierarchy is incorrect.
Notice how Camp's reply avoids all of the points which were made against his
argument. Camp does not provide us with an example of a non-nested pattern
produced by common descent. He reiterates the claim that various processes "work
against" a nested pattern, when in fact those very processes create a
nested pattern. These processes cannot be "invoked in whatever blend is
necessary to explain whatever pattern is found." Yes, "bare" common descent may
not state anything specifically about these processes, but universal common
descent is constrained by gradualism, as has been explained many times
over. We know empirically the maximum rates of anagenesis, character loss, and
character replacement -- such processes can be used in scientific explanations, of
course, but there are limits on what rates can be used. This was already
addressed specifically in predictions 22, 23, 24, 28, and
Furthermore, we also know that convergence happens (it is a prediction of
natural selection and is observed regularly in the wild and in the lab).
However, true structural convergence, in which distantly related taxa perform
the same functions with the same underlying structures, is rare relative to
divergence. In fact, when considering DNA sequence evolution, we can calculate
very precisely what rates of convergence are reasonable and what rates are
Michael Denton's Views of the Nested Hierarchy
Camp then goes on to quote another confused anti-evolutionist, Michael
Denton, in support of his assertion that common descent does not predict a
"In the final analysis the hierarchic pattern is nothing like the
straightforward witness for organic evolution that is commonly assumed.
There are facets of the hierarchy which do not flow naturally from any
sort of random undirected evolutionary process. If the hierarchy
suggests any model of nature it is typology and not evolution. How much
easier it would be to argue the case for evolution if all nature's
divisions were blurred and indistinct, if the systema naturalae
was largely made up of overlapping classes indicative of sequence and
In evolution, "sequence and continuity" are truly only displayed in the time
dimension. Horizontal slices of time may hint at continuity, especially between
closely related species -- but branching and divergence from a common ancestor
predicts nested hierarchies at any given time, not a continuum. Denton simply
did not understand common descent when he wrote this passage (his views have
since changed). Common descent is the hypothesis that all species are strictly
genealogically related. That means that species should be organizable into a
family tree. It is very easy to see that a family tree gives nested hierarchies
at any given single point in time. If all of nature were "blurred and
indistinct," if the "systema naturalae was largely made up of overlapping
classes," this would not indicate common descent, it would indicate something
like Lamarck's organic progression or the medieval view of the "great chain of
being." Camp has replied to these comments:
Next, Dr. Theobald chides me for quoting "another confused
anti-evolutionist," Michael Denton. As an aside, I find it fascinating
that, according to Dr. Theobald, Denton "doesn't understand even the
most fundamental evolutionary concepts." It is fascinating because one
often hears that nothing in biology makes sense except in light of
evolution. And yet, Denton, being ignorant of the most fundamental
evolutionary concepts, managed to earn a Ph.D. in developmental biology
(in addition to an M. D.), to write or co-author over seventy articles
in professional journals, and to work for decades as a genetics
researcher. Apparently knowledge of evolution is irrelevant to a career
I am confident that Michael Denton has contributed greatly to scientific
knowledge in his area of expertise. Yet, Camp's logic here is wanting. Someone
can have a successful scientific career, especially in an applied field, without
understanding the theory behind the science they practice. Plenty of people
drive cars and fly in planes who understand not a thing about how cars and
planes work. Most people who consider themselves "computer literate" don't
really understand how computers do their thing at the most basic level (and I
count myself among them). I can program with languages such as sed, awk, Perl,
Python, C, C++ and some Java and Fortran -- but that doesn't mean I understand how
to make a functional silicon computer chip. Even silicon chip designers often
know extremely little quantum mechanics, even though electromagnetic theory and
quantum mechanics ultimately explain the behavior of all electronic devices.
Likewise, someone can be a good medical doctor without understanding why the
drugs they prescribe work effectively, and someone can do plenty of good
biological research without understanding evolutionary biology. Nevertheless,
nothing in computing makes sense except in the light of microchip technology,
nothing in microchip technology makes sense except in the light of quantum
mechanics, nothing in the automobile industry makes sense except in the light of
mechanics and thermodynamics, nothing in aviation makes sense except in the
light of aerodynamics, nothing in medicine makes sense except in the light of
biochemistry, and nothing in biology makes sense except in the light of
It is not to the benefit of Camp's argument that he uses quotes from Denton's
book, Evolution: A Theory in Crisis. This book is ridden with errors,
false "facts," illogic, and uninformed dialectics. As one of a myriad of
examples, immediately preceding the paragraph quoted by Camp above, Denton
"There is another stringent condition which must be satisfied if a
hierarchic pattern is to result as the end product of an evolutionary process:
no ancestral or transitional forms can be permitted to survive." (Denton
1986, p. 136, emphasis in the original).
This is false and nicely illustrates the wanton ignorance concerning basic
evolutionary concepts displayed in this book. This passage is, additionally,
directly pertinent to the present discussion of nested hierarchies. Denton
immediately follows the above statement with:
"This can be seen by examining the tree diagram above on page 135. If any
of the ancestors X, Y and Z, or if any of the hypothetical transitional
connecting species stationed on the main branches of the tree, had survived
and had therefore to be included in the classification scheme, the
distinctness of the divisions would be blurred by intermediate or partially
inclusive classes and what remained of the hierarchic pattern would be highly
1986, p. 136)
The absurdity of these statements is evident when one includes the ancestors
X, Y, and Z in Denton's nested hierarchy figure. All the ancestors (including a
hypothetical transitional connecting species, W) fit
in the existing nested hierarchy just fine, without blurring the distinctness of
divisions or contributing disorder to the hierarchical pattern. If the author
could not even work out the simple evolutionary predictions based upon his very
own figures and examples, it is no wonder that he wrote that "the hierarchic
pattern is nothing like the straightforward witness for organic evolution that
is commonly assumed."
Figure C2. A phylogeny and the corresponding
nested hierarchy, as given by Michael Denton (Denton
1986, p. 134-135). Denton's figure is reproduced in black.
Additions by Theobald are shown in red. (Figure reproduced with permission
from Random House Publishers.)
Dr. Theobald's disparaging comment notwithstanding, Denton's point
about the nested hierarchy observed in nature has merit. The
discreteness or discontinuity of the groupings does not flow naturally
from a random, undirected evolutionary process. One must explain why the
morphological space between the groups exists, as opposed to the
divisions being blurred and indistinct. The point is not that
evolutionists cannot explain it but that it is something that requires
If that is the point then it is a moot one for our present discussion. All
natural phenomena require an explanation, scientifically. Is there supposed to
be something problematic about that? In fact, "discreteness or discontinuity of
the groupings" does "flow naturally from a random, undirected
evolutionary process." Extinction is an observable fact, both in the fossil
record and in the present. Extinction is all that is needed to cause
discontinuity (though other processes can also be involved). Extinction is also
largely random and undirected.
Interestingly, it appears that Denton has finally rectified his
misunderstanding about nested hierarchies and common descent, since in his
latest book he unconditionally assumes the validity of the nested hierarchy,
common descent, and the "tree of life" (Denton
1998, pp. 265-298). For example, in the chapter entitled The Tree of
Life from Nature's Destiny, Denton discusses the phylogeny of several
closely related species (the primates) and directly contradicts his previous
misstatements presented by Camp above:
"In the case of primate DNA, for example, all the sequences in the
hemoglobin gene cluster in man, chimp, gorilla, gibbon, etc., can be
interconverted via single base change steps to form a perfect evolutionary
tree relating the higher primates together in a system that looks as natural
as could be imagined. There is not the slightest indication of any
1998, p. 277)
This was written by the same man who scribed:
"Each class at a molecular level is unique, isolated and unlinked by
intermediates. Thus, molecules, like fossils, have failed to provide the
elusive intermediates so long sought by evolutionary theory." (Denton
1986, p. 290)
One wonders how Camp can feel justified in quoting Denton's past confusions
about common descent. Camp has responded to this:
Dr. Theobald apparently misunderstands Denton's point in the quote,
as he claims that Denton subsequently contradicted himself in opining
that the hemoglobin gene cluster in primates was not discontinuous. Just
because Denton believes there is no discontinuity requiring an
explanation in that particular instance does not mean he denies there is
discontinuity elsewhere. So Dr. Theobald's comment ("One wonders how
Camp can feel justified in quoting Denton's past confusions about common
descent") is misguided.
Contrary to Camp's later protestations, here Denton is not referring to
primate DNA as an exception -- he now sees it as an example of a generality of
life. That is why Denton prefaces this case with "for example." One wonders if
Camp has read Denton's new book.
Unsupported Theology and Projection
At this point, Camp leaves science and enters into theological arguments:
The notion that the nested hierarchy of organisms is incompatible
with creation is based, not on science, but on the unprovable
theological assumption that if God created life he would do it in some
other way. As biologist Leonard Brand explains:
The hierarchical arrangement of life illustrated in Fig. 9.6 has
been used by Futuyma (1983) and others as evidence that life must have
evolved. They believe that if life were created, the characteristics
of different organisms would be arranged chaotically or in a
continuum, not in the hierarchy of nested groups evident in nature. If
we think of that concept as a hypothesis, how could it be tested?
Actually, to state how a Creator would do things and then show that
nature is or is not designed that way is an empty argument. Such
conjecture depends on the unlikely assumption that we can decide what
the Creator would be like and how he would function. (Brand, 155.)
In fact, no theological assumptions or arguments are made at all in the
essay. The "29 Evidences" is not an argument against creation -- it is the
scientific argument for common descent, no more, no less. The evidence for
common descent can only be evidence against creation if one believes the two are
mutually incompatible. A belief that Divine creation and common descent are
mutually exclusive alternatives is indeed a theological assumption, and it is
one that Ashby Camp makes, not I.
If Camp has independent evidence that a Creator has created life to result in
a nested hierarchical classification, let him present that evidence. If the
hypothesis that a Creator created in this manner is testable and falsifiable,
let Ashby Camp tell us how. Personally, I agree with Brand when he says that "to
state how a Creator would do things and then show that nature is or is not
designed that way is an empty argument. Such conjecture depends on the unlikely
assumption that we can decide what the Creator would be like and how he would
1997, p.155). Camp also concurs, as he says that predictions about how God
would create are "based, not on science, but on the unprovable theological
assumption that if God created life he would do it in some [specific] way." The
creation hypothesis that a Creator created life with nested hierarchies is
therefore not scientific; as Brand and Camp note, it is untestable. It is highly
ironic that Camp has tried to turn a fatal weakness of creationism into a
weakness of the theory of common descent.
Throughout his criticism, indeed in every section, Camp relentlessly accuses
me of making theological assumptions which I do not make. Frankly, I find this
to be offensive, since in reality it is Ashby Camp who makes the theological
assumptions and then projects his bias on me. I personally believe that an
omnipotent, omniscient Creator could have created in any manner that he chose.
For a theist, the pertinent question is not "what is an omnipotent Creator
capable of?" but rather "how exactly did/does the Creator create?". The first
question is purely theological, and as such is left unaddressed in the "29
Evidences"; in contrast, the second question is one that science can answer
(given the assumption of a Creator).
The "29 Evidences" concerns scientific evidence only -- that means
only hypotheses which can be tested against hard empirical evidence,
only hypotheses that can be either confirmed or falsified in principle.
Unfortunately, Camp forwards numerous scientifically meaningless, untestable
"creation hypotheses" throughout his critique, apparently under the
self-deceiving illusion that they have some relevance to the present issue.
However, in the quoted section above, Camp states outright that conjecture about
how a Creator created is not scientific, because such conjecture cannot be
tested and because we cannot know the Creator's intent in the first place. Thus,
every alternative "creation hypothesis" that Camp proffers is irrelevant by his
Camp has written in defense of his unsubstantiated theological accusations:
Dr. Theobald next charges me with wrongful imputation of a
theological assumption. ...
First, everyone realizes that universal common ancestry is compatible
with certain theories of divine creation (e.g., theistic evolution).
However, it is incompatible with the claim that the founding members of
various groups were created separately by God. That claim is a specific
case of non-universal common ancestry. So "29 Evidences for
Macroevolution" is an argument against creation in that sense.
If Camp is correct, then all scientific theories and conclusions are
arguments against some creation "theory." Amos 4:13 states that God creates the
wind (the Hebrew verb for "create" here, "bara," is the same as that in the
first chapter of Genesis). Does that mean that meteorology is an argument
against Divine creation? Someone who reads Amos "literally" could argue that God
separately creates all winds. Thus, appeals to "highs" and "lows" or "cold
fronts" and "warm fronts" are all arguments against the separate creation of
winds. In fact, by Camp's logic, all scientific theories are arguments against
God's direct Divine intervention in some phenomenon that we observe. If
electromagnetic theory is true, that means that God does not miraculously cause
magnets to stick to refrigerators or cause positively charged things to attract
negatively charged things.
Though I disagree, suppose for the sake of argument that Camp is correct that
scientific conclusions are necessarily arguments against direct Divine action.
Just because we conclude something does not mean that we assumed that
conclusion in the premises of our argument. Just because one could (in
principle) conclude from the "29 Evidences" that God did not separately create
species does not mean that was an assumption of the argument. Camp's first
point, thus, does nothing to support his accusation that I have made certain
theological assumptions (against special creation) in the arguments presented in
the "29 Evidences."
Note, however, that Camp is strictly incorrect to state that common ancestry
is necessarily "incompatible with the claim that the founding members of various
groups were created separately by God." As I pointed out earlier in the
discussion here of Prediction 2,
God could have created all species independently and miraculously, yet
gradually -- a theological position compatible with universal common descent.
Gradual Divine direction of evolution is consistent with universal common
descent, even though there is currently no scientific evidence for such a
belief. This concept has been pointed out before by other evolutionary
biologists -- see, for instance, the conclusion of Kathleen Hunt's Transitional
Vertebrate FAQ, in the discussion of possible consistent
models, especially "
So, Camp does not simply assume that Divine creation and common descent are
necessarily mutually exclusive alternatives. Camp also makes the additional
theological assumption that God could not have created species (founding members
and/or others) independently and gradually. In contrast, no such
theological assumptions (or conclusions) are made in the "29 Evidences."
More Unfamiliarity with the Scientific Method
Camp continues in defense of his accusations:
Second, if evidence is compatible with separate creation by God
(non-universal common ancestry), it is not probative of the contrary
proposition (universal common ancestry). Since one can judge nested
hierarchy to be incompatible with separate creation by God only if one
assumes that God would not separately create organisms in a nested
hierarchy, the inference of universal common ancestry from the evidence
of nested hierarchy contains a latent theological assumption. Because
Dr. Theobald is unaware of this, he takes great umbrage at what he
perceives to be my erroneously attributing the assumption to him. His
pique is unwarranted.
Once again, Mr. Camp persists in accusing me of making a theological
assumption which I do not make. Nowhere in the "29 Evidences" is it stated that
"God would not separately create organisms in a nested hierarchy" or anything
similar. Nowhere is it stated or implied that God would or would not create or
do anything in any manner. Of course God could have created organisms in
a nested hierarchy. If there is scientific evidence for this, then perhaps Mr.
Camp should present it.
Yet again, this sophistry evidences an unfamiliarity with the scientific
method. The first sentence in Camp's quote above is false. In science, evidence
can be compatible with a hypothesis and still be "probative of the contrary
position" (for those, like me, who are unfamiliar with the words "probative of" -- here it
means "evidence for"). Camp insists that the "evidence is compatible with
separate creation by God," which of course it is, but that is a moot point as
far as science is concerned.
Scientific theories are not judged simply by their compatibility with the
evidence and data. All physical evidence and data are compatible with an
infinite number of unscientific "hypotheses." As a simple extreme example, I
could hypothesize that the entire universe was miraculously created 5 minutes
ago, with everything already set in place to appear as if it were much older
(our memories included). Such a hypothesis is completely compatible with the
available evidence and data. Go ahead, prove me wrong! And there lies the
rub -- this hypothesis is not scientific because there is no possible evidence that
could stand in contradiction to its predictions. Any and all evidence is
compatible. It is untestable in principle, even though it is logically
consistent with the data -- but we since cannot test it, we have no scientific
reason to conclude that it is likely, and thus it is not scientific. Ironically,
Camp himself went to great lengths to make this very point about special
creation and the nested hierarchy. Camp stated:
The notion that the nested hierarchy of organisms is incompatible
with creation is based, not on science, but on the unprovable
theological assumption that if God created life he would do it in some
Camp quoted Brand in support:
"to state how a Creator would do things and then show that nature is
or is not designed that way is an empty argument. Such conjecture
depends on the unlikely assumption that we can decide what the Creator
would be like and how he would function" (Brand
Obviously Camp agrees that there is no way to prove this theological
assumption wrong. Therefore, we both agree that is not scientific. This is true
even though this "creation hypothesis" is logically consistent with the
evidence. The "29 Evidences," however, concerns not what is simply logically
consistent with the data. The "29 Evidences" concerns scientific evidence,
testable hypotheses, and scientific conclusions. Supposedly, that was
also the object of Camp's criticism. Camp began his rebuttal with these words:
In "29 Evidences for Macroevolution," Dr. Theobald sets forth the
evidence that he believes proves scientifically that all organisms share
the same biological ancestor. In this critique, I argue that his
evidence is insufficient to establish that proposition.
In contrast to his claims, Mr. Camp is preoccupied with establishing the
trivial fact that special creation by miraculous means is logically "compatible"
with the evidence -- an obvious point which is essentially inarguable. However,
this point has nothing to do with science. Camp's "Critique" of the scientific
evidence concerns unprovable theological assumptions, not scientific
Camp continues with his original critique:
It may be that the nested hierarchy of living things simply is a
reflection of divine orderliness. It also may be, as Walter ReMine
suggests, that nested hierarchy is an integral part of a message woven
by the Creator into the patterns of biology. (See, e.g., ReMine,
367-368, 465-467.) The point is that the hierarchical nature of life can
be accommodated by creation theory as readily as by evolution.
Accordingly, "[i]t is not evidence for or against either theory."
Creation theory can, to my knowledge, accommodate any possible outcome and is
therefore untestable, unfalsifiable, and unscientific. If Camp has an opposing
view and has examples of observations that would falsify creation theory, let
him present them. Common descent, on the other hand, cannot accommodate any
outcome; common descent predicts observable nested hierarchies. If rates of
evolution are extremely fast (or extremely slow), nested hierarchies will be
observed only for very recently diverged taxa (or for very distantly related
taxa). Fortunately, we observe a range of evolutionary rates in different
characters and thus observe nested hierarchies at many levels in biology.
It is worth pointing out here that it is in fact possible to have a
"reciprocal" pattern from nested hierarchies. Mathematically, a nested hierarchy
is the result of specific correlations between certain characters of organisms.
When evolutionary rates are fast, the characters become randomly distributed
with respect to one another, and the correlations are weakened. However, the
characters could also be anti-correlated in theory -- it is possible for them to be
correlated in the opposite direction from what produces nested hierarchies, as
discussed in Prediction
2. The observation of such an anti-correlated pattern would be highly
inconsistent with common descent, regardless of evolutionary rates.
Confusion about Evolutionary Theory
Camp concludes his criticism of this point with an attack on the very notion
of cladistic classification:
Dr. Theobald's claim that "specially designed objects like buildings,
furniture, cars, etc." cannot be classified in a nested hierarchy
requires elaboration. In terms of mere classification, it is incorrect.
Buildings and vehicles have both been used as examples of nesting (Ridley
1993, 52-54; Fastovsky and Weishampel, 51-53; Brand, 165-166).
Camp's assertion stems from a misunderstanding, one that is addressed in
detail in the new version of the "29 Evidences" under prediction
2. Some authors have used more familiar objects for illustrating nested
hierarchies; however, these are only for explanatory purposes and are not meant
to be strict analogies. Of course buildings and cars can be arbitrarily sorted
into nested hierarchies. The point is that they do not form natural
nested hierarchies; they do not meet the mathematical requirements of nested
hierarchies. Camp seems not to understand this point, in spite of the fact that
one of his favorite anti-evolutionists explains it clearly:
"Any system of objects can be forcibly classified into a nested hierarchy.
Some systems do not have to be forced, rather they display a nested pattern
with clarity without having to be coerced. Life has such a pattern. There are
no tetrapods that are not based on the vertebrate body plan. There are no
amniotes that are not based on the tetrapod body plan. There are no mammals
that are not also amniotes. These are the familiar examples, and many more can
be given. They are powerful generalizations. Life is like nested Chinese boxes
of subsets within subsets within subsets. Life is comprised of nested
similarities. This significant pattern must be explained." (ReMine
1993, p. 344)
And common descent explains it.
Camp concludes this misunderstanding with a quote from a well-known
evolutionary biologist, which only appears to support his point:
"Any set of objects, whether or not they originated in an
evolutionary process, can be classified hierarchically. Chairs, for
instance, are independently created; they are not generated by an
evolutionary process: but any given list of chairs could be classified
hierarchically, perhaps by dividing them first according to whether or
not they were made of wood, then according to their colour, by date of
manufacture, and so on. The fact that life can be classified
hierarchically is not, in itself, an argument for evolution." (Ridley
Camp carefully and quite misleadingly omits the very next sentence:
"The argument for evolution comes from a particular property of the
classificatory hierarchy, the kind of traits that define it." (Ridley
Ridley goes on to make a good qualitative argument for the uniqueness of
genealogically generated nested hierarchies, of how life's nested hierarchy is
not "forced." Ridley was not arguing that organisms do not fall into natural
nested hierarchies, as Camp implies. By omitting the additional sentence which I
have provided, the Ridley quote appears to mean something other than it did in
the original context. Thus, this is a classic example of the fallacy of quoting out of context.
Furthermore, Ridley was of course unaware of the more rigorously defined
mathematical differences between "pseudo"-hierarchies of things like cars,
chairs, or buildings and the real hierarchies of organisms or languages, because
the mathematics for examining cladistic hierarchical structure was first worked
out six years later, in 1991.
Camp has since replied to this criticism
of his argument given above:
I wrote that "[i]n terms of mere classification," the statement was
incorrect. To back up the claim that such specially designed objects can
indeed be classified in a nested hierarchy (regardless of whether they
possess genuine hierarchical traits), I pointed out that they are often
used as examples of nesting.
It is in that context that I quoted Ridley. The point was that "[a]ny
set of objects, whether or not they originated in an evolutionary
process, can be classified hierarchically" (emphasis supplied), not that
all sets of objects possess bona fide hierarchical traits. I omitted
Ridley's statement that life exhibits a genuine hierarchy because it was
irrelevant to my point. So Dr. Theobald has quoted me out of context in
accusing me of quoting out of context! He then builds on his confusion
in suggesting that I intentionally sought to mislead people ("Camp
carefully and quite misleadingly omits the very next sentence").
First, I never suggested that Camp intentionally sought to mislead people. I
did claim that Camp "carefully" omitted an important part of Ridley's
statements, and Camp has admitted to that. I also claimed that omitting that
sentence is misleading, which it is. It makes it appear as if Ridley meant
something different from what he intended. Whether Camp intentionally
wrote that line to mislead people is something only Camp himself can know.
Second, I did not quote Camp out of context. I included Camp's sentence "In
terms of mere classification, it is incorrect." Third, it is now quite clear
that Camp understands that there are important differences between artificial
and "bona fide" nested hierarchies:
... I was not quoting Ridley to deny there is a difference between
artificial and genuine hierarchies but only to support my contention
that specially designed objects can be classified in a nested hierarchy
That is a very trivial point. It is irrelevant to the present discussion,
since the issue at hand concerns genuine hierarchies like those found in life,
not artificial hierarchies which can be arbitrarily constructed from specially
designed objects. Someone could artificially classify pennies as "square
rabbits," too. It is of course valid to state that pennies cannot be classified
as squares or rabbits, because pennies obviously do not satisfy the requirements
of geometrical squares or biological animals.
In this light, it is curious that Camp entered an extended discussion about
how someone could artificially categorize certain non-hierarchical things in
nested hierarchies. That point was not made in Prediction 2 of the "29
Evidences" -- so why include the Ridley quote to begin with? The point was simply
that species form natural nested hierarchies, while chairs, books, the
planets, the elements, and fundamental particles do not -- and Camp evidently
agrees. Was it a mistake to expect that Camp's arguments and supporting quotes
were actually intended to be directed against the evidence for common descent?
That is of course what I assumed when I read the Ridley quote, and I suspect
many other readers made the same assumption.
Prediction 3: Convergence of independent phylogenies
More Misrepresentation of Evolutionary Theory
Common descent predicts that independent determinations of phylogenetic
histories should be similar. Once again, Camp denies that this is a prediction
of common descent. However, this time, his basis for denial is the belief that
this prediction has been falsified, and since scientists do not toss out common
descent, this must not be a prediction of common descent. The error lies in the
belief that this prediction has been falsified. Camp says:
The important point is that it is not a prediction of the hypothesis
of common ancestry that phylogenies constructed from comparisons of
biological molecules will match phylogenies constructed from comparisons
of morphology. This is obvious from the fact molecular and morphological
phylogenies often are inconsistent, and yet the hypothesis of common
descent is not considered falsified. The discordant data are simply
accommodated by the theory.
Camp is correct that often independently determined phylogenies are not
exactly the same (i.e. they are incongruent). But in science, independent
measurements of some value (such as a physical constant like the charge of the
electron, the mass of the proton, or the speed of light) are never exact. There
always exists some error in the measurement, and all independent measurements
are incongruent to some extent. Of course, the true value of something is never
known for certain -- all we have are measurements that we hope approximate the true
value. Scientifically, then, the important relevant questions are "When
comparing two measurements, how much of a discrepancy does it take to be a
problem?" and "How close must they be to be a strong confirmation?" Scientists
answer these questions with probability and statistics. This issue is
specifically addressed in the revised version of the "29 Evidences" under prediction
3. The upshot is that the degree to which even the most incongruent trees
match is extraordinary. Penny and Hendy have done a detailed statistical
analysis of the significance of similar phylogenetic trees, and here is their
"Biologists seem to seek the 'The One Tree' and appear not to be satisfied
by a range of options. However, there is no logical difficulty in having a
range of trees. There are 34,459,425 possible trees for 11 taxa (Penny
et al. 1982), and to reduce this to the order of 10-50 trees is
analogous to an accuracy of measurement of approximately one part in
and Hendy 1986, p. 414)
For a more realistic universal phylogenetic tree with dozens of taxa
including all known phyla, the accuracy is orders of magnitude smaller (better).
So Camp is incorrect on two counts. First, common descent does indeed predict
that independently determined trees should be similar -- if there really is a true
genealogical tree of species, how could this not be the prediction? This is
exactly why all the scientists that Camp quotes are concerned about incongruent
Second, when analyzed statistically, the trees are stunningly
similar -- even the most incongruent ones. Incongruent trees are a "problem" in the
sense that we biologists wish to attain perfection in our science, and
incongruent trees are imperfect. Even so, the differences are just much too
minor to falsify common descent; to the contrary, they confirm this prediction
of common descent to a much higher degree than is found in any other scientific
Camp has offered a defense of his erroneous views:
Dr. Theobald misses the point in arguing that even the most
incongruent phylogenies match to an extraordinary degree. Since his
evidence is the alleged fulfillment of a falsifiable prediction, the
issue is not the degree to which phylogenies match but the degree to
which the bare hypothesis of common ancestry demands that they match.
Without some constraint on the operation of processes that work against
congruity, which constraint the hypothesis does not provide, nonmatching
phylogenies are compatible with the hypothesis. There is no falsifiable
prediction of congruity.
"The degree to which the bare hypothesis of common ancestry demands that
[independently derived phylogenies] match" was and is clearly stated: they
must match with statistical significance (for more discussion see Prediction
3). This requirement has been stated, tested, and fulfilled in the primary
scientific literature on several occasions (Baldauf
et al. 2000; Penny
and Hendy 1986; Penny
et al. 1982; Penny
et al. 1991). Since it was possible, indeed highly probable, for
phylogenies to match without statistical significance or to mis-match
with statistical significance, the prediction of congruity is easily falsifiable
if common descent is false. Thus, Camp is wrong on this account, and he has
failed to even address the real issue (the extremely high statistical
significance of the match between independently derived phylogenies).
Unfortunately, Camp's argument is fundamentally flawed at a much deeper
level. Camp contradicts himself; in his eagerness to "disprove" common descent,
Camp simultaneously argues for two opposing views. Camp states:
... molecular and morphological phylogenies often are inconsistent,
and yet the hypothesis of common descent is not considered falsified.
The discordant data are simply accommodated by the theory.
and follows with this a few paragraphs later:
The availability of such ad hoc adjustments for resolving
incongruities makes the claim of falsifiability an illusion. Any result
can be accommodated by the theory by revising one or more of the
Why is there any discordant data if any result is changed at will with ad
hoc revising of the assumptions? These statements are contradictory, and
both cannot be true. In fact, both are false. Camp has objected to my analysis
... there is no contradiction in saying that inconsistent molecular
and morphological phylogenies are discordant data and saying that such
inconsistencies can be accommodated by ad hoc adjustments.
However, that was not Camp's original claim. He was claiming that
inconsistent phylogenies exist in the scientific literature and that
incongruities are generally resolved in practice by ad hoc adjustments
(e.g. "the obvious point that assumptions are adjusted to accommodate discordant
data" and "discordant data are simply accommodated by the theory"). That claim
is self-contradictory, since differences between phylogenies in the scientific
literature cannot be both inconsistent and accomodated simultaneously.
Note that, if this is not really what Camp meant, then he has no valid
point. Just because inconsistencies can be accommodated, in principle, by
invoking ad hoc arguments does not mean that scientists actually do so or
that this kind of 'assumption-adjusting' is considered fair game. In principle,
all possible conflicting observations in any scientific discipline can be made
consistent with any theory by invoking ad hoc arguments (formally known
as the Duhem-Quine thesis). Therefore, if Camp actually meant this, it is an
argument that is not specific to evolutionary biology, since it can be applied
to all of science.
But, as detailed below, Camp is incorrect on both counts regardless. First,
though strictly incongruent phylogenies exist, the vast majority of phylogenies
are consistent within error and with statistical significance -- which is
what counts in science. Second, ad hoc adjustments are not used
liberally -- their use is severely constrained by gradualism and by what has been
empirically observed. Camp disregards both of these facts.
A Malign Accusation Based on Misunderstanding of the Scientific Method and
... molecular and morphological phylogenies often are inconsistent,
and yet the hypothesis of common descent is not considered falsified.
The discordant data are simply accommodated by the theory.
The availability of such ad hoc adjustments for resolving
incongruities makes the claim of falsifiability an illusion. Any result
can be accommodated by the theory by revising one or more of the
Biologists cannot "adjust the assumptions" to give any desired result. Camp
is making the slanderous claim that biologists unethically manipulate their data
to result in a predetermined outcome. Here's a test: if Camp's malign accusation
is true, he should be able to adjust the assumptions of a phylogenetic analysis
to result in a tree of my choice. Using any molecular data of his choice, Camp
should be able to generate a phylogenetic tree with a standard tree-building
program (such as PAUP, Phylip, MacClade, etc.) that places chimps closest to
fish, humans closest to birds, cows closest to insects, and bacteria closest to
marsupials, specifically as shown below:
C F H B Cw I B M
\/ \/ \ / \/
\ / \/ /
\/ / /
\ / /
\ / /
The truth is that Camp will be unable to meet this challenge. All scientists,
including biologists, must deal with this annoying thing called "reality." Real
data cannot be arbitrarily fit to any model with equal success. Even more
importantly, scientists do not uncritically accept ad hoc assumptions.
Valid assumptions must be reasonable and independently testable.
Mr. Camp has addressed this challenge:
For making the obvious point that assumptions are adjusted to
accommodate discordant data, Dr. Theobald falsely accuses me of
slandering biologists with the charge that they "unethically
manipulate their data to result in a predetermined outcome"
(emphasis supplied [by Camp]).
This is no false accusation. Unjustified, ad hoc manipulation of data
is unethical behavior in science, especially if it is used to make data appear
to agree with a predetermined outcome. This is precisely what Camp is claiming,
and thus he is asserting that biologists unethically manipulate data. If Camp
believes biologists do this, he is obligated to provide an example of where
researchers have intentionally used ad hoc, scientifically unjustified
revisions of the underlying assumptions of a phylogenetic analysis in order to
make discordant phylogenies appear more congruent. Since Camp is claiming that
this is a general feature of evolutionary phylogenetic analysis (and not
just a rare, exceptional behavior), he should be able to provide many
examples from throughout the modern peer-reviewed scientific literature
(preferably from articles less than 5-10 years old). In the event that Camp is
unable to do this, I strongly suggest that he retract his slander.
Camp, however, has attempted to justify his accusations:
Did anyone accuse Schwabe and Warr of slander ...?
Does it matter? Does Camp believe his statements are justified simply because
other people have done the same? Camp's question is an overt use of the "two wrongs make a right"
fallacy (very similar to "tu quoque").
Did anyone accuse Schwabe and Warr of slander for saying that "Ad hoc
arguments can be invented" to explain inconsistent molecular phylogenies
in a way consistent with universal common ancestry or for saying that
the ability to invoke such arguments robs universal common ancestry of
its vulnerability to disproof?
Whether anyone accused them of slander is beside the point. However, Camp
claimed more than the above. Camp didn't just claim that these ad
hoc arguments and processes could be invoked, he claimed that they
are invoked by biologists to manipulate the outcomes of their analyses
("the obvious point that assumptions are adjusted to accommodate discordant
data"). Camp's allegations go beyond the discussion by Schwabe and Warr. Schwabe
and Warr never claimed that "Any result can be accommodated by the theory ...".
Camp's question misses the point altogether.
In any event, Schwabe and Warr wrote those comments over eighteen years ago.
Mountains of molecular data have been acquired and analyzed since then, and new
techniques and technologies have been developed. It is possible that Schwabe and
Warr's statements were applicable at the time -- but, regardless, they are
certainly inapplicable now (see the discussion
of Schwabe and Warr's article below). It is Camp's responsibility to make
sure that the sources he quotes are not outdated, and that they are applicable
to current science.
Dr. Theobald's challenge to construct a molecular phylogeny to his
specification ... misses the point. The point is that his specified
molecular phylogeny would be compatible with the bare hypothesis of
universal common ancestry.
In other words, Camp admits he is unable to meet the specified challenge. By
doing so, Camp concedes that it is untrue that "Any result can be accommodated
by the theory by revising one or more of the underlying assumptions". As clearly
evidenced by the exchange above, that was the point being discussed
here -- not that any "phylogeny would be compatible with the bare hypothesis of
universal common ancestry."
This last point, which Camp urges is the point, is irrelevant. It is
true only in an extremely trivial sense -- if we ignore all other relevant
data and the requirements of common descent on our planet. But we cannot ignore
this data, since the only way we can test the theory of common descent is with
independently acquired evidence. All individual pieces of data, in isolation,
are consistent with any theory. However, theories are not tested with single
measurements, like a single phylogenetic tree based on one gene. Theories are
tested with specific data from specific cases which are compared with each
other -- this is a basic scientific concept.
The point is that his specified molecular phylogeny would be
compatible with the bare hypothesis of universal common ancestry.
Camp's point, though trivially true, is impotent as a criticism of a theory.
It is analogously true that a specified value of 6x10-7
m3kg-1s-2 for the universal Newtonian constant
of gravitation would be compatible with the "bare" hypothesis of universal
gravitation. But the true value is (approximately) 6.673x10-11
m3kg-1s-2, and the specified hypothetical value
is massively inconsistent with all current measurements which have approximated
this universal constant. Again, we test universal theories with specific data
from independent measurements. This is a fundamental aspect of the scientific
method, one that Camp ignores when he argues that my "specified molecular
phylogeny would be compatible with the bare hypothesis of universal common
The fact remains that the specified phylogeny given above is massively
inconsistent with the morphological phylogeny and all known molecular
phylogenies, and the specified phylogeny cannot be constructed with any known
molecular sequences using current phylogenetic reconstruction programs,
regardless of how the assumptions are adjusted. This is exactly what one would
predict if common descent is true, and this is precisely why common descent is a
falsifiable hypothesis. My specified tree could be compatible with common
descent in a different world -- but in our world it is incompatible with
common descent, and the real data do not support such a fictitious phylogeny.
In discussing incongruent phylogenies, Camp uses a favorite quote of
"scientific" creationists by Christian Schwabe and Gregory Warr (Camp gets
Schwabe's name wrong -- it is not "Christopher") (Schwabe
and Warr 1984):
Two years earlier, Schwabe and Gregory Warr were equally blunt in
their criticism of molecular phylogenies. They saw the field of
molecular evolution as being mired in subjectivity driven by an a
priori commitment to universal common ancestry. They wrote:
We believe that it is possible to draw up a list of basic rules
that underlie existing molecular evolutionary models:
- All theories are monophyletic, meaning that they all start with
the Urgene and the Urzelle which have given rise to
all proteins and all species, respectively.
- Complexity evolves mainly through duplications and mutations in
structural and control genes.
- Genes can mutate or remain stable, migrate laterally from
species to species, spread through a population by mechanisms whose
operation is not fully understood, evolve coordinately, splice, stay
silent, and exist as pseudogenes.
- Ad hoc arguments can be invented (such as insect vectors or
viruses) that can transport a gene into places where no monophyletic
logic could otherwise explain its presence.
This liberal spread of rules, each of which can be observed in use
by scientists, does not just sound facetious but also, in our opinion,
robs monophyletic evolution of its vulnerability to disproof, and
thereby its entitlement to the status of a scientific theory. The
absolute, explicit and implicit, adherence to all the monophyletic
principle and consequently the decision to interpret all observations
in the light of this principle is the major cause of incongruities as
well as for the invention of all the genetic sidestepping rules cited
above. (Schwabe and Warr, 467.)
Camp quotes Schwabe and Warr without providing any hard evidence to back up
their claims. Schwabe and Warr wrote these statements nearly twenty years ago,
when we had only a tiny fraction of the presently known molecular sequences (in
1984 we had less than two-hundredths of one percent of the number of sequences
2002). Frankly, Schwabe and Warr were wrong. Just because a scientist makes
an argument does not mean that his argument is correct. Just because it is
published does not make it correct. Publication in peer-reviewed journals is
only the first step of scientific peer-review. Just because a scientific
argument might have been correct eighteen years ago does not mean it is
applicable today. Schwabe and Warr stated their case, but the evidence acquired
since has not supported their views. Science is weighed and measured with hard
evidence and specific examples. Does Camp give any to support Schwabe and Warr's
Let's examine Schwabe and Warr's claims one at a time:
First, it is untrue that "All theories are monophyletic ...". The hypothesis
of the universal common ancestry of species is not the same as universal common
ancestry of proteins and/or genes. In fact, it is virtually certain that genes
and proteins have arisen independently many times throughout evolutionary
history. We know of many mechanisms for creating proteins and genes de
novo. For instance, we have observed the evolution of a completely novel
protein in bacteria by mutations which translate a gene in a new reading frame.
The resulting protein has no similarity to the initial one (Ohno
Second, increases in complexity due to gene duplications and mutations have
been observed in the wild and the lab (Copley
1998, p. 274; Lederberg
and Lederberg 1952; Lee et
al. 1998; Ohno 1984;
et al. 1983; Orser
and Lange 1994; Salamone
et al. 2002). For example, Flavobacterium recently evolved the
ability to metabolize the exclusively man-made chemical nylon as its sole carbon
source. This ability required the duplication and mutation of genes for three
different enzymes (Negoro
et al. 1994; Ohno 1984;
et al. 1983). These results have also been duplicated in the lab (Prijambada
et al. 1995). Some of these studies have demonstrated that new
enzymes have evolved with increased specificity for their substrates (Salamone
et al. 2002). This is not ad hoc nor is it "liberal" -- it is
Third, we observe stochastic (random) mutation of genes regularly (which
means we expect that often, simply due to chance, genes will not mutate), we
regularly observe lateral transfer (Dowson
et al. 1994; Lorenz
and Wackernagel 1994; Ochman
et al. 2000; Widdowson
et al. 2000), we have observed genes spread through populations (yes,
even when mechanisms are not well understood) (Raymond
et al. 2001), we find silent genes, we find splicing genes (Hastings
and Krainer 2001), we find pseudogenes (Mighell
et al. 2000). We have observed genes evolve coordinately (concerted
and Radding 1975; Szostak
et al. 1983; Nagylaki
and Chovnick 1981; Petes
et al. 1991; Strachan
et al. 1985; Lamb and
Helmi 1982). Again, none of this is ad hoc, nor is it "liberal"; it
Fourth, countless times we have observed viral vectors insert genes where
monophyly could not explain it (Hindmarsh
and Leis 1999; Urnovitz
and Murphy 1996). Neither is this ad hoc -- it is factual.
Finally, Schwabe and Warr state that biologists resorted to "the invention of
all the genetic sidestepping rules cited above" in order to explain their
observations. That is preposterous. Biologists did not "invent" these
mechanisms; they were empirically discovered both in the wild and in the lab
over the past few decades. Now, nearly twenty years after Schwabe and Warr wrote
these words, we have delineated these various processes in considerable detail,
both mechanistically and structurally at the molecular level.
Camp has replied:
The bare hypothesis of universal common ancestry places no constraint
on the operation of these processes. It therefore makes no falsifiable
prediction that molecular phylogenies will converge on the standard
morphological phylogeny. So, contrary to Dr. Theobald's assertion, it is
not that I believe the prediction has been falsified. Rather, I believe
the claim of falsifiability is an illusion.
As stated many times over in this reply and in the "29 Evidences," gradualism
severely constrains the operation of all evolutionary processes. If we invoke
any of the processes that Schwabe and Warr are concerned about, they must be
used in a manner consistent with what has been observed. We cannot use any and
all rates of mutation -- for example, some rates are too high to be reasonable
(e.g. greater than an average of 10-6 per base per generation in
mammals). Contrary to Schwabe and Warr's overstated claims, it is not ad
hoc to explain observations with mechanisms that have been observed. It is
not a "liberal spread of rules." It is, however, good scientific
In many, probably most, cases these proposed mechanisms are independently
testable. As just one example, horizontal gene transfer by viral insertion into
a host genome leaves easily recognizable tell-tale signs in the sequences
surrounding the inserted gene. If a gene has been inserted by a viral vector,
these tell-tale sequences should be there.
In fact, it would be unjustified and ad hoc to be aware of all these
observations over the past 50 years of various genetic mechanisms and to argue
that they were not important in the past 3.5 billion years of evolutionary
history. Camp, Schwabe, and Warr appear to be miffed that biology is complex,
and that there are many ways for genes to be transmitted between organisms
besides linear inheritance between generations. But this is real science, the
real world, real biology -- the real world is not simple, and biology is the most
complex of sciences. Biological data demand complex explanations. Just because a
scientific explanation is complex does not mean it is unfalsifiable. Very clear,
unambiguous ways exist to falsify common descent, and demonstrating pervasive,
highly incongruent phylogenies is one of them, in spite of these various
mechanisms which could be used to explain relatively minor incongruencies. For
more explanation, refer to prediction
Furthermore, Schwabe and Warr grossly overstate the importance of known
incongruent phylogenies. As addressed in prediction
3 and as illustrated by the Penny and Hendy comment above, incongruent data
in phylogenetic analyses are much less problematic than incongruent data in
other scientific fields, such as particle physics and gravity. As stated above,
in reality the known incongruent trees are a "problem" only in the sense that we
biologists wish to attain perfection in our science, and incongruent trees are
Camp's fallacious appeal to authority
falls apart upon even cursory inspection. It is yet another example of using
outdated (and marginal) science in an attempt to bolster a flawed argument.
Insufficient Knowledge of Basic Molecular Biology and Genetics
Camp even doubts that correspondence between molecular and morphological
phylogenies would be evidence for common descent:
Even if a morphological phylogeny was matched closely by multiple
molecular phylogenies, that would not prove that the groups in question
descended from a common ancestor. The molecular differences could be
linked to the morphological differences for some other reason.
Though Camp's point is valid, it already has been addressed extensively in Prediction
17, and Prediction
18 of the "29 Evidences." It is relatively simple to find genes or parts of
genes (the molecular evidence) that are not functionally linked to morphology.
Confusion about Evolutionary Theory
Camp goes on to quote Hunter concerning this point:
Hunter illustrates the point this way:
Penny obtained his trees by culling those that were most
parsimonious -- that is, he selected the trees that showed the least
amount of evolutionary change to represent the history of life. The
first problem is that Penny's method works perfectly fine on things we
know did not come about via Darwinian evolution. For example, Penny's
method would also claim that automobiles evolved from one another.
As pointed out above, Hunter is incorrect. Hunter makes the bold claim that
"Penny's method would also claim that automobiles evolved from one another" in
the absence of any evidence to support that claim. Automobiles might give a most
parsimonious tree (though this is not assured), but even if they do, the
resulting tree will be bunk. It will not satisfy the mathematical requirements
for nested hierarchies, and the reasons are explained in Prediction
2. If Camp and Hunter think otherwise, they should determine a phylogenetic
tree of cars, using standard phylogenetic programs, that has statistically
significant high values of cladistic hierarchical structure. To really drive the
point home, they could derive two trees independently, and then show that they
match with statistical significance. If they are correct, they could easily
prove their point -- but in reality they will be unable to do so.
Camp continues with Hunter's quote:
Consider a group of vehicles, beginning with a small economy car and
increasing in size to larger cars and to minivans and large-sized vans.
One could quantify several aspects of the vehicle designs, such as tire
size, steering mechanism, engine size, number of seats and so forth.
Presupposing the evolutionary paradigm and searching for parsimonious
relationships, we would find that most of the design measures suggest
the same relationship. The smaller vehicles have smaller tires, manual
steering, smaller engines, and fewer seats. The larger vehicles have
larger tires, power steering, larger engines, and more seats. In other
words, the groupings suggested by the different design measures (tire
size, steering mechanism, engine size, etc.) tend to be similar. But of
course, the family of automobiles did not evolve from one another via
random mutations. The groupings of the design measures are a natural
result of engineering and have nothing to do with Darwinian evolution.
How then can Penny's results provide "strong support" for evolution?
Hunter's example is erroneous for another reason -- he has chosen characters
that are not independent. This is a big "no-no" in cladistic analysis, and it is
a rudimentary issue that is addressed early on in any introductory text on
phylogenetic analysis. When using characters of organisms in a cladistic
analysis, biologists attempt to use characters that are as functionally and
developmentally independent of one another as possible. For instance, the size
of an animal is only one character. Of course larger animals will in general
have larger bodies, larger legs, and larger heads, just as in Hunter's example
larger cars have larger tires, larger engines, etc. To be valid, "largeness"
cannot be counted more than once. The very easy solution, which is regularly
used by biologists, is to measure the relative sizes of different
characters. For instance, having a femur/tibia ratio of 3 is a different
character from having a femur/tibia ratio of 1/2, regardless of the overall
length of the bones. Biologists know that they must normalize for size, and
instead they concentrate on structural details. Hunter's example is thus a straw
Penny's analysis (Penny
et al. 1982) used five genes, four of which are functionally
independent; thus, the result that trees made from several different independent
genes match with statistical significance is indeed extremely strong support for
common descent. For Hunter's analogy to be valid, he would have to claim that
phylogenetic trees made only with cars' steering wheels will match phylogenetic
trees made only with cars' tires and trees made only with cars' headlights and
trees made only with cars' engines and trees made only with cars' transmissions.
Such a claim would be false, since cars with similar tires (e.g. similar
width/diameter ratio, manufacturers, tread, color, materials, etc.) do not
generally also have similar engines (e.g. similar manufacturer, injection
systems, cylinder arrangement, orientation, etc.), or headlights (e.g. similar
shape, brightness, manufacturer, bulb type, position, number, etc.), or
transmissions, or steering wheels.
Thus, Hunter's analogy is false
for multiple reasons. Hunter's example of how cars' characters can be analyzed
to infer a phylogeny is quite different from how real organisms' characters are
analyzed by biologists when inferring a phylogeny.
Camp believes that "it would not be surprising from a creation perspective to
find that biochemical similarities increase in relation to other similarities of
the creatures being compared," and he quotes anti-evolutionists Duane Gish and
Leonard Brand in support:
"We know, for instance, that man is more similar to a chimpanzee than
he is to a bat; that he is more similar to either a chimpanzee or a bat
than he is to a crocodile or a flea. Man, chimpanzee, and the bat are
mammals. The creationist would expect, therefore, that his protein, DNA,
and RNA molecules, those macromolecules that are among the most
important molecules in metabolism, would be more similar to those of the
chimpanzee and to those of the bat than to those of the crocodile or the
flea." (Gish, 277-278.)
"Anatomy is not independent of biochemistry. Creatures similar
anatomically are likely to be similar physiologically. Those similar in
physiology are, in general, likely to be similar in biochemistry,
whether they evolved or were designed." (Brand, 156.)
Both are wrong. There is no known biological reason, besides common descent,
to suppose that similar morphologies must have similar biochemistry. At first,
the statements made by Gish and Brand may seem obviously correct to the
layperson, but all of molecular biology refutes this "common sense" correlation.
In general, similar DNA and biochemistry give similar morphology and function,
but the converse is not true -- similar morphology and function is not necessarily
the result of similar DNA or biochemistry. The reason is easily understood once
explained; many very different DNA sequences or biochemical structures can
result in the same functions and the same morphologies. As a very close analogy,
consider computer programs. Netscape works essentially the same on a Macintosh,
an IBM, or a Unix machine, but the binary code for each program is quite
different. Computer programs that perform the same functions can be written in
most any computer language -- Basic, Fortran, C, C++, Java, Pascal, etc. and
identical programs can be compiled into binary code many different ways.
Furthermore, even using the same computer language, there are many different
ways to write any specific computer program. In the end, there is no reason to
suspect that similar computer programs are written with similar code, based
solely on the function of the program. This is the reason why software companies
keep their source code secret, but don't care that competitors can use the
program -- it is essentially impossible to deduce the program code from the
function and operation of the software. The same conclusion applies to
biological organisms, for very similar reasons.
Leonard Brand is evidently oblivious to this basic conclusion from modern
genetics and molecular biology, since Camp quotes him stating:
|"An alternate, interventionist hypothesis is that the cytochrome
c molecules in various groups of organisms are different (and
always have been different) for functional reasons. ...If we do not base
our conclusions on the a priori assumption of megaevolution, all
the data really tell us is that the organisms fall into nested groups
without any indication of intermediates or overlapping of groups, and
without indicating ancestor/descendant relationships. The evidence can
be explained by a separate creation for each group of organisms
represented in the cytochrome c data." (Brand, 158-159.)
Brand's entire argument is predicated upon his first sentence -- "An alternate,
interventionist hypothesis is that the cytochrome c molecules in various
groups of organisms are different ... for functional reasons." Brand's
hypothesis is uncharacteristically testable, which is fortunate. If we can
demonstrate that cytochrome c molecules from different organisms are not
different for functional reasons, then his argument is moot. In fact, it has
been shown that the human cytochrome c protein works just fine in yeast
(a unicellular organism) that lacks its own native cytochrome c gene,
even though yeast cytochrome c differs from human cytochrome c
over 40% of the protein. Even the cytochrome c genes from tuna, pigeon,
horse, Drosophila fly, and rat all function well in yeast that lack their
own native yeast cytochrome c. Furthermore, extensive genetic analysis of
cytochrome c has demonstrated that the majority of the protein sequence
is unnecessary for its function in vivo (a point covered in detail in the
original version of the "29 Evidences" under Prediction
17). Thus, Brand's "alternate hypothesis" is false, as is the rest of his
argument. The cytochrome c gene is not exceptional in this regard -- similar
results have been found for all other ubiquitous genes tested. Biochemically,
the reason for this observation is easily explained. Most of the sequence of a
protein, like cytochrome c, is used for structural elements. As long as
these structural parts of the protein fold into the same structure, the exact
sequence is inconsequential. From X-ray crystallographic studies of the atomic
structures of proteins, we know that many of the amino acids in any protein are
not even used for structure and that many different amino acid sequences can
fold into the same structure. Thus, since structure determines function, we
fully expect that proteins with very different sequences will give the same
function, and that is exactly what we observe. Accordingly, as explained earlier
and contrary to Camp's argument, there is no reason to assume (aside from common
descent) that similar morphologies and functions are due to similar molecular
Herring: Insufficient Knowledge of "Neo-Darwinism"
Camp finds yet another "problem" with the cytochrome c data and its
implications for common descent:
The cytochrome c data on which Dr. Theobald relies present
some puzzles from a neo-Darwinian perspective. First, the cytochromes of
all the higher organisms (yeasts, plants, insects, fish, amphibians,
reptiles, birds, and mammals) exhibit an almost equal degree of sequence
divergence from the cytochrome of the bacteria Rhodospirillum. In
other words, the degree of divergence does not increase as one moves up
the scale of evolution but remains essentially uniform. The cytochrome
c of other organisms, such as yeast and the silkworm moth,
likewise exhibits an essentially uniform degree of divergence from
organisms as dissimilar as wheat, lamprey, tuna, bullfrog, snapping
turtle, penguin, kangaroo, horse, and human.
Though mechanisms of adaptive evolutionary change are not addressed in the
"29 Evidences," Camp inserts a red herring here and
shifts the subject by questioning the efficacy of "neo-Darwinism" to explain the
degree of divergence observed in the cytochrome c sequences of various
organisms. Camp's line of argumentation regarding rates is off the point. Common
descent states nothing specifically about evolutionary rates, whether they must
be fast, slow, variable, or constant, and the most commonly used phylogenetic
methods make no rate assumptions. Common descent is, in general, consistent with
a large range of evolutionary rates, as long as the rates satisfy the
requirement of gradualism. Explaining rates is the specific realm of genetic
mechanisms, such as genetic drift, neutral theory, natural selection, gene flow,
sexual selection, mutation, etc.
Nevertheless, Camp's discussion of cytochrome c rates is flawed and is
not based in a working knowledge of the fundamentals of modern genetics or
molecular biology. One of the main consequences of the functional redundancy of
protein sequences (discussed in preceding paragraphs) is "neutral" evolution.
The neutral theory describes the genetic behavior of mutations in protein and
DNA sequences that have no, or very slight, selective effects. As mentioned
above, about 70% of the cytochrome c protein is redundant. Changes in
this 70% have virtually no effect upon function, and thus no selective
effect -- this 70% is selectively "neutral." One of the major predictions of the
neutral theory is that the overall rate of evolution in neutral regions (where
"evolution" means change in sequence) will be equal to the background rate of
mutation. Mutations are largely due to factors that are relatively constant
between different organisms, such as chemical and physical events (such as the
spontaneous breaking or formation of bonds in DNA) and "errors" in the
ubiquitous DNA repair machinery. Thus, neutral theory predicts that neutral
rates of evolution should be nearly constant between organisms for functionally
equivalent genes. It directly follows that the divergence of cytochrome c
sequences should be nearly equal between two organisms and their last common
ancestor. For example, according to the theory of common descent, bacteria,
horses, and insects all share a common ancestor in the remote past. If rates of
neutral evolution have been constant since that common ancestor, then the
cytochrome c proteins of bacteria, horses, insects all should have
evolved by the same amount since their last common ancestor. Accordingly, the
divergence of cytochrome c between bacteria and horses should be nearly
the same as the divergence between bacteria and insects. This is the answer to
Camp's next question:
Why would the sequence divergence of cytochrome c between
bacteria and horses be the same as the divergence between bacteria and
insects? The presumed evolutionary lineage from the ancestral cell to a
modern bacterium differs radically from the presumed evolutionary
lineage from the ancestral cell to a modern horse, both of which differ
radically from the presumed evolutionary lineage from the ancestral cell
to a modern insect. How could a uniform rate of divergence have been
maintained through such radically different pathways? According to
Michael Denton, a molecular biology researcher, "At present, there is no
consensus as to how this curious phenomenon can be explained." (Denton
And, as we have shown earlier, Michael Denton knows very little basic
The most likely reason why the rate of divergence has
been quite uniform in all these "radically different" lineages is that
cytochrome c does the exact same thing in all these lineages (it
transports electrons in the fundamental cellular process of oxidative
phosphorylation), and the mutations that do not destroy or change the function
of cytochrome c are necessarily neutral. A better question is "why would
the rate be nonuniform in these different lineages?" Contrary to Camp's
suggestion, there is a consensus explanation for the cytochrome c
sequences provided by neutral theory, the one just explicated above in
simplified form. Wesley Elsberry gives a more detailed explanation of the
cytochrome c data in "Sequences
and Common Descent." It is worthy to note here that the consensus
explanation for cytochrome c sequence divergence does not involve natural
selection, but only uses neutral theory, mutation, and purifying selection. To
my knowledge, none of these standard genetic theories has been seriously
criticized by anti-evolutionists (especially the "scientific" creationists).
An inquisitive person might ask further: "Should the divergence between the
cytochrome c sequences from different organisms be exactly equivalent?"
And the answer is no -- mutation, recombination, and sexual reproduction are all
stochastic processes (i.e., they have a large probabilistic element to them). We
expect, even with exactly equivalent background rates of mutation, that amounts
of divergence will be similar, but not equivalent. As with any stochastic
process, there is a finite probability that "surprising" things might happen.
For instance, whenever we flip 50 quarters, we expect that on average 25 will be
heads and 25 will be tails. However, the probability that we will flip
exactly 25 heads and 25 tails is rather small (~11%). There is a 0.1%
chance that we will flip more than twice as many heads than tails. This means
that if we repeat our 50-flip experiment 1000 times, we expect to flip
more than twice as many heads as tails at least once (perhaps more). As Penny
et al. put it in their article "Testing the Theory of Descent":
"From the proposed stochastic nature of the mechanism of mutation and
selection it would be surprising if the trees were identical. Indeed, it would
be more devastating to Darwinism if different sets of short sequences always
gave identical trees." (Penny
et al. 1991)
Thus, given the stochastic nature of genetics, we in fact expect that
independently derived trees occasionally will not match exactly and that rates
of divergence will vary for the same reasons.
Camp evidently does not understand the probabilistic nature of genetics,
since he is surprised at a small minority of "anomalous" cytochrome c
Moreover, the notion that the rates of divergence remain uniform
regardless of evolutionary pathway does not fit all of the cytochrome
c data. For example, referring to Dr. Theobald's Figure 1
(reproduced above), lampreys, carp, and bullfrogs allegedly shared a
common ancestor above the node labeled "vertebra." Since that time, the
branch leading to carp and bullfrogs evolved independently of the branch
leading to lampreys. If the rates of cytochrome c divergence
remain uniform regardless of evolutionary pathway, then the degree of
sequence variance between the cytochrome c of lampreys and carp
would be essentially the same as the degree of variance between the
cytochrome c of lampreys and bullfrogs. That is not the case. The
variance between the cytochrome c of lampreys and carp is 12%,
whereas the variance between lampreys and bullfrogs is 20%. (See matrix
in Davis and Kenyon, 37.)
These results are expected if genetics is fundamentally probabilistic instead
of deterministic, as it is. Camp states: "If the rates of cytochrome c
divergence remain uniform regardless of evolutionary pathway, then the degree of
sequence variance between the cytochrome c of lampreys and carp would be
essentially the same as the degree of variance between the cytochrome c
of lampreys and bullfrogs." This is incorrect, and displays a lack of
understanding of probability and statistics, leading to Camp's commission of a
Uniform rates are expected to give unequal results (see the discussion on
mathematics below after the green box). Camp's statements are a nice example of
the fallacy of
accident (Dicto Simpliciter). Furthermore, Camp is incorrect in his
details. I cannot speak for the original citation (Davis
and Kenyon 1993), but the values that Camp gives for the divergences of
lamprey, carp, and bullfrog cytochrome c are incorrect. The true
divergence between the cytochrome c of lampreys
is 19%, and the divergence between lampreys and bullfrogs
is 20%. Camp has since explained that he was using an outdated source (over
thirty years old) for these figures, yet he still "stand[s] by" these
figures -- even though the sequences I have given above were updated in 1981, 1984,
and 2000 (this is easily verified simply by clicking the links I have given).
Camp continues with his surprise that some of the cytochrome c
sequences appear anomalous:
Second, the sequences of cytochrome c sometimes differ
inversely to the presumed evolutionary proximity of the organisms being
compared .... The cytochrome c of the rattlesnake varies in 22
places from that of the turtle but only in 14 places from that of a
human. ... the cytochrome c of the human varies in 12 places from
that of a horse but only in 10 places from that of a kangaroo. ... Such
discrepancies between traditional phylogenies and those based on
cytochrome c are well known.
There are many problems with this passage. As stated before, such results are
expected if heredity is a stochastic process, as it is. Because genetics is
stochastic, the theory of common descent does not predict that phylogenetic
trees made with single genes will perfectly match other phylogenetic trees -- they
must be similar, but not necessarily identical. As already explained in the "29
"Gene trees are not equivalent to species trees: from simple
Mendelian genetics we know that genes segregate individually, and that
throughout time individual genes do not necessarily follow organismic
genealogy. An obvious example is the fact that while you may have brown eyes,
your child may have the genes for blue eyes -- but that does not mean your child
is not your descendent, or that your brown-eyed children are more closely
related to you than your blue-eyed children. Including multiple genes in the
analysis is a solution to this conundrum." (Avise
and Wollenberg 1997)
Furthermore, Camp has made a more fundamental error here, indicative of his
unfamiliarity with modern evolutionary theory. Camp is directly comparing raw
distance data (the number of cytochrome c sequence differences) to character
data (the morphological phylogenetic data) and expecting them to match, which is
improper. In the early days of phylogenetic analysis, researchers used raw
distance data to construct phylogenetic trees because distance algorithms are
simple and fast (they take little computation time). However, for strong
theoretical and empirical reasons, uncorrected distance data is known to be an
unreliable basis for phylogenetic analyses (though it is approximately correct
under certain conditions). Today, instead of using distance algorithms,
evolutionary biologists primarily use more correct (and much more
computationally intensive) algorithms, such as maximum parsimony or maximum
likelihood, which are based on direct character information. Thus, it is a
meaningless criticism to point out that raw molecular distances are sometimes
not reflected by character-based phylogenies -- that situation is in fact
predicted by evolutionary theory.
Additionally, Camp incorrectly states that "discrepancies between traditional
phylogenies and those based on cytochrome c are well known." Camp is
referring to out-dated cytochrome c analyses which did not include
statistical tests of support for the branches in the phylogenies. When only
statistically reliable branches are considered, the cytochrome c
phylogenies are completely congruent with traditional morphological
phylogenies -- even when the cytochrome c phylogeny is approximated with naive, raw
Apparently, Camp not only misunderstands basic genetics but also has a deep
misunderstanding of basic mathematics (probability and statistics), as he later chides in
In other words, evolution expects uniform divergencies [sic]
of protein sequences, but it also expects nonuniform divergencies if and
when they arise. It is an amorphous theory indeed.
There is nothing inconsistent with a uniform rate and nonuniform results.
That is basic statistics. As a very simple example, in the above discussion of
quarter flipping, the rate of "heads" is exactly 0.5 heads per flip. This rate
is exactly constant. However, there is nothing unusual (or "amorphous")
about flipping five heads in a row, or five tails in a row (corresponding to an
average observed rate of one head per flip and zero heads per flip,
respectively). Such results are expected if coin flipping is a stochastic
process, as it is. We expect these results about 6% of the time. In fact, the
outcome of a stochastic process, like coin flipping, radioactive decay, or
spontaneous mutation, should approximate a Gaussian bell-shaped curve (also
known as a "normal curve"), as explained in any entry-level probability
and statistics text.
Figure C1. Distribution of genetic distances
between human and mouse genes. The histogram is the actual data
from 2,019 human and mouse genes. The solid curve shows the expected
distribution of genetic distances assuming only a constant rate of
background mutation (~10-9 substitutions per site per year)
(reproduced from Figure 3a in Kumar and Subramanian 2002).
Similarly, if rates of molecular evolution are exactly constant, we
expect that the genetic divergences between species will be unequal in most
cases. In fact, we expect that neutral genetic divergences will be distributed
about a Gaussian bell-shaped curve centered on the average rate of molecular
evolution. Many species should have more divergence than average (like the
rattlesnake cytochrome c), and many species should have less divergence
than average (like the kangaroo cytochrome c). Likewise, we expect that,
if background mutation rates are exactly constant, genetic divergences
between neutral regions of different genes between two species will also be
distributed about a bell-shaped curve. In fact, this is precisely what is
observed (e.g. see the data for humans and mice in Figure C1 at left; Kumar
and Subramanian 2002). For instance, from basic probability theory, we
expect that 15% of genes between humans and mice should evolve over 36% faster
than the average constant rate (that is 1.36 times the average rate), over 2%
should evolve about 70% faster than the average constant rate, and that 0.5%
should evolve over 85% faster than the average rate. And, as the figure shows,
this is exactly what we observe in humans and mice. Note, this means that in a
comparison of one hundred randomly sampled human and mouse genes, we expect that
the most divergent gene will have 0% similarity in neutral regions, while the
least divergent gene will have nearly 100% similarity in neutral regions (see
the lower left tail of the bell curve in Figure C1). These results are
predicted, based upon simple math, if the average background mutation rate is
completely constant in both the human and mouse lineages. This fact
illustrates nicely why it is premature to base strong evolutionary conclusions
on an analysis of only one gene (like the cytochrome c gene) or even a
few genes; strong conclusions can only be based upon a large sampling of genes.
It is rather presumptuous to label a theory "amorphous", when said theory
simply follows basic laws of mathematics.
Even including all the known discrepancies, the cytochrome c phylogeny
and the traditional morphological phylogeny match to an extremely high degree
with extremely high statistical significance (Penny
et al. 1982). And, as expected, including more genes in the analysis
increases the correspondence between phylogenetic trees (Penny
et al. 1982; Baldauf
et al. 2000; Hedges
and Poling 1999). In the end, the molecular phylogenetic data, such as the
cytochrome c data, provide one of the strongest and most irrevocable
confirmations of common descent.
Prediction 4: Possible morphologies of predicted common
More Misrepresentation of Evolutionary Theory: Erroneous Logic
Universal common ancestry affirms only that all creatures descended
from the same ancestor. There is nothing about that affirmation that
requires conformity to the standard phylogenetic tree.
Again, Camp is mistaken. If all organisms are united by descent from a common
ancestor, then there is one single true historical phylogeny for all organisms,
just like there is one single true historical genealogy for any individual
human. It follows that if there is one unique universal phylogeny, then all
organisms fit in that phylogeny uniquely. In other words, all organisms, both
past (e.g. fossils) and present, must conform to the true phylogeny. Since the
standard phylogenetic tree is the best approximation of the true historical
phylogeny, we expect that all fossilized animals should conform to the standard
phylogenetic tree within the error of our scientific methods. If fossilized
animals do not, then there are only two logical possibilities -- either our
estimation of the true phylogeny is incorrect, or there is no true phylogeny
(i.e. common descent is false). This last point leads in to Camp's next mistake:
A phylogenetic tree is merely a diagram that reflects current
evolutionary thinking about the relationships of the taxa included.
Branches are arranged on the tree on the assumption of evolution and
according to perceived similarities in selected traits. The
relationships of some branches are viewed more dogmatically than the
relationships of others, but none of the branches are set in stone.
No branches are viewed "dogmatically" -- some branches have strong support from
the data and are very unlikely to be incorrect if common descent is true, while
other branches are known with less confidence. Thus, fossilized organisms that
contradict the very well-supported branches would be inconsistent with common
Misunderstanding of the Scientific Method
Camp has replied:
It is self-evident that the bare hypothesis of universal common
ancestry affirms only that all creatures descended from the same
ancestor. It would be consistent with all phylogenies rooted in a
single ancestor, and therefore it does not predict any particular
phylogeny, such as the standard phylogeny. For stating this obvious
fact, Dr. Theobald accuses me of misrepresenting evolutionary theory.
Universal common descent is not "consistent with all phylogenies rooted in a
single ancesotor." Universal common descent predicts that there is only one true
phylogeny, not multiple phylogenies. Since it predicts a unique historical
phylogeny, the existence of different phylogenies rooted in a common ancestor is
incompatible with common descent. Camp is correct that common descent "does not
predict any particular phylogeny," but that is a moot point. We must
examine the data and infer the correct particular tree.
Similarly, Newton's Universal Theory of Gravity affirms that all masses
accelerate towards each other proportional to a universal graviational constant,
G. However, Newton's theory is not consistent with all values of
G, because the theory predicts that there is only one true value
of G, not multiple Gs. Of course Newton's theory
does not predict any particular value of G. But that is a
moot point. We must examine the data and infer the correct particular value for
Mr. Camp misrepresented evolutionary theory because he said:
Universal common ancestry affirms only that all creatures descended
from the same ancestor. There is nothing about that affirmation that
requires conformity to the standard phylogenetic tree.
That is false. Universal common ancestry also requires that there is only one
historical phylogenetic tree. Thus, independent determinations of the standard
phylogenetic tree should conform to each other. The absurdity of Camp's
misrepresentation is clear when the analogous statement is made of Newton's
Universal Theory of Gravity:
"Universal gravity affirms only that all masses accelerate towards each
other. There is nothing about that affirmation that requires conformity to the
standard constant G."
Of course independent measurements should conform to the standard constant
G. Careful independent measurements of G should give
values that agree reasonably well. If they don't, there is something wrong with
the theory. Likewise, careful independent determinations of the standard
phylogenetic tree should agree reasonably well. If they don't, there is
something wrong with the theory. This is a very basic scientific concept. Camp
continues his reply:
The problem is that, since we do not know the true evolutionary
history of organisms, we cannot know whether the standard phylogeny is
Camp is incorrect. In science, there are ways to determine the true
evolutionary history (such as cladistics and molecular phylogenetic
reconstruction methods), and we can test those results to see whether the
standard phylogeny is accurate. That is what the entire "29 Evidences" is about. This
situation is paralleled in all scientific disciplines. We do not know the true
gravitational constant, G, yet, in science, there are ways to
determine it. Additionally, we can test our results from these measurements and
see whether the consensus value for G is accurate.
My point was that the inaccuracy exposed by any nonconforming
organism could be corrected by adjustments to the phylogeny at a level
above the hypothesized universal common ancestor. So, contrary to Dr.
Theobald's claim, the hypothesis of universal common ancestry would not
be proven false by the discovery of a nonconforming organism. The
standard phylogeny simply would be shown to be in need of modification
at some level.
This is false. There are some mildly nonconforming organisms that could
possibly be incorporated and there are some that cannot. There is no way to
modify the standard phylogeny to incorporate a mammal with feathers or a bird
with a mammalian head and a placenta. Such organisms will not fit anywhere in
the phylogeny. Including a half-mammal/half-bird organism in a cladistic
analysis of mammals, reptiles, and birds destroys the hierarchical structure in
the resulting cladogram (e.g. as measured by the consistency index, CI, the
retention index, RI, the homoplasy index, HI, or the rescaled consistency index,
RCI) and greatly reduces the cladogram's resolution (e.g. as measured by the
statistical bootstrap support for all the branches in the tree). Normally,
including real, allowable intermediates increases the hierarchical structure and
resolution of a cladogram (or at least does not affect it much).
Every scientific theory can accommodate incongruent data to some extent, yet
every scientific theory also has its limits. For example, Newton's Universal
Theory of Gravity predicts that the universal gravitational constant,
G, is constant in space and time. G should be the
same everywhere on the earth and in space. The way we test this is to make
multiple independent measurements of G, at different times,
different locations, and using different methods. Newton's theory can (and does)
accommodate minor discrepancies (as explained and discussed in Prediction
3), but there are some values which, if measured, would be too far out to be
reconciled. The same is true of universal common descent, and a mammal-bird is
an example that is too far out to be reconciled.
More Misunderstanding of the Scientific Method
Since phylogenies are by nature provisional, the suggestion that the
hypothesis of common descent would be falsified by "[a]ny finding of
mammal/bird intermediates" is mistaken. Should a strikingly birdlike
mammal be discovered, the standard tree simply would be modified to
accommodate the new creature, after wrangling over its placement in the
This demonstrates an underlying misconception of the scientific method.
Everything in science is by nature provisional. However, some things are
more "set in stone" than others, and that is where the concept of falsifiability
comes in. Even Camp's anti-evolutionist source Walter ReMine understands that
science is at once provisional and falsifiable:
"The criterion of falsifiability indicates science is tentative. Science
never achieves certainty. Science is not rigid and dogmatic ... Because our
observations are limited, we can only attain fine shades of near
certainty. ... While science is tentative, it is not flimsy. Science can carry
enough weight that we often speak of a given theory as a fact. ... Science is
also tentative about falsifying a theory. It can be difficult to falsify a
theory with all the finality we would like. ... By testing ... we attain
greater confidence in identifying false hypotheses." (ReMine
1993, p. 34, emphasis in the original)
Though ReMine often misses the mark, these statements capture the essence of
testability in science quite well. The standard phylogenetic tree, as currently
supported by massive amounts of data, is highly inconsistent with true
mammal-bird intermediates. The phylogenetic tree could not be modified to
accommodate such creatures -- they would not fit anywhere.
A Glut of Errors: The Fallacy of Ignoratio
Elenchi, Multiple Self-
contradictions, and Distortion of a Scientific Controversy
Ironically, the inflexibility of this aspect of the standard phylogenetic
tree is well-evidenced by Camp's next statements:
The ease with which this precise adjustment could occur was
illustrated two decades ago, when "[t]he reality of the 'mammal-bird,' a
hypothetical common ancestor of birds and mammals, [was] a contentious
issue in modern systematics." (Mike Benton, 18.) Brian Gardiner's
cladistic analysis indicated that birds were most closely related to
mammals, which relationship was supported by two Cambridge scientists'
analysis of molecular data. .... Branches can be rearranged, even
between mammals and birds, without skipping a beat in terms of
commitment to common ancestry.
Camp's use of the Gardiner controversy misses the point entirely; Camp's
reply does not address the issue at hand. It is an example of the ignoratio elenchi
fallacy. Camp was responding to the claim that a mammal-bird is predicted
not to exist by current evolutionary theory, based upon common descent
and the consensus phylogenetic tree. Thus, any finding of a mammal-bird
intermediate form in the fossil record would be a falsification. However, the
Gardiner controversy does not concern the finding of an intermediate form that
is contrary to phylogenetic expectations. Rather, it concerns uncertainty in the
consensus phylogenetic tree based upon an analysis of living organisms.
These are two entirely different issues.
All scientific measurements have some level of uncertainity. This is not a
problem in science; it just means we have room to make a more accurate
measurement, which, of course, is always desirable. To provide a valid
counter-example, Camp needs to provide an instance of where biologists have
accepted the finding of an organism that was contrary to very well-supported
portions of the consensus phylogeny (branches with very low uncertainty). Camp
does not do this -- we did not find a mammal-bird intermediate. Instead, he
provides an irrelevant, out-dated example of where biologists have had
difficulty resolving a branching order in the consensus phylogeny.
However, Camp is, again, self-contradictory -- his argument is inconsistent. How
can "mammal-birds" at once be contentious and also be accommodated with "ease",
"without skipping a beat"? They can't! The Benton article to which Camp refers
1984) is wholly devoted to exploring the extremely surprising (and, at the
time, quite troubling) idea that the standard phylogenetic tree could be so
very, very wrong about birds and mammals. There was nothing "easy" about this
possibility -- it threatened to shake the very roots of the well-established
phylogeny of life. For example, in response to Gardiner's outlandish analysis,
zoologist Barry Cox wrote this in a News and Views article in Nature:
"[Gardiner is] now assaulting even the most fundamental roots of the
systems of relationship that the traditional evolutionary morphologists have
developed. ... Gardiner has now used cladistic techniques to transform the
whole system of tetrapod classification. ... The results are so different ...
that a headlong collision is inevitable, for there can be no minor shifting of
viewpoints or emphasis that could lead to a reconciliation or synthesis. ...
Gardiner's suggestions [are] completely at odds with the palaeontological
record ..." (Cox 1982)
Does this sound like biologists accepted this "precise adjustment" with
"ease"? Does this sound like these "Branches can be rearranged, even between
mammals and birds, without skipping a beat"? In a vain effort to make his point,
Camp felt it necessary to grossly misrepresent the true status of the
controversy. In his in depth criticism of Gardiner's analysis, Oxford zoologist
T. S. Kemp wrote:
"... many, probably the great majority of vertebrate biologists have
dismissed Gardiner's hypothesis as simply outrageous ..." (Kemp
1988, p. 69)
Notwithstanding Camp's unfounded statements, Gardiner's analysis was not
incorporated or reconciled, nor were branches rearranged in the consensus
phylogeny. In reality, the "contentious issue" was short-lived, as it was soon
shown by several independent researchers that Gardiner's cladistic analysis was
fundamentally flawed at many levels (Benton
et al. 1988; Hopson
1991; Kemp 1988;
1991). Likewise, the supposed corroborating molecular evidence was analyzed
incorrectly. At the time (the early '80's), cladistics and molecular
phylogenetics were just coming into their own, and the proper techniques were
still getting worked out. In fact, improvements are still being made today, as
is true of technological innovations in all scientific fields. In the end, all
these analyses contributed positively to our knowledge via improved phylogenetic
techniques -- but they did not radically alter the consensus phylogeny. Quite the
opposite, the improved analyses have confirmed that earlier biologists were
Camp has responded:
In the face of this example that contradicts his allegation that a
mammal-bird intermediate would falsify universal common ancestry, Dr.
Theobald goes on the offensive. ... Dr. Theobald is not thinking
clearly. The issue is whether the discovery of a mammal-bird
intermediate would falsify universal common ancestry. The fact is that
those scientists who concluded that birds were most closely related to
mammals (and thus that mammal-bird intermediates existed) remained fully
committed to the hypothesis of universal common ancestry. They embraced
the mammal-bird link without skipping a beat in terms of commitment to
As stated above, Camp misses the point. As he says, the issue at hand is that
a mammal-bird discovery would falsify common descent. The issue is not
whether the bird-reptile-mammal branching order is uncertain or well-resolved.
If some scientists conclude that birds are most closely related to mammals (as
Gardiner did), and some other scientists conclude that birds are most closely
related to reptiles (as held by the consensus), that is simply an example of
uncertainty in branching-order of the consensus phylogeny. It does not address
whether the finding of a certain intermediate form (like the mammal-bird) would
be inconsistent with highly-resolved regions of the consensus phylogeny. In
other words, Camp has not provided an example "that contradicts [the] allegation
that a mammal-bird intermediate would falsify universal common ancestry." Camp
has side-stepped that issue. Ironically, Camp fully admits this in his response:
The scientific dispute centered on whether mammal-bird intermediates
existed (i.e., on whether Gardiner's conclusion was valid), not on
whether their existence would require rejection of universal common
ancestry. The fact most scientists resisted and ultimately rejected the
conclusion that birds were most closely related to mammals is irrelevant
to whether the discovery of a mammal-bird intermediate would falsify
universal common ancestry.
Precisely. Let's pause here to let the irony of Camp's words soak in:
Dr. Theobald is not thinking clearly.
The issue is whether the discovery of a mammal-bird intermediate
would falsify universal common ancestry. ...
[Gardiner's] conclusion that birds were most closely related to
mammals is irrelevant to whether the discovery of a mammal-bird
intermediate would falsify universal common ancestry. ...
[Gardiner's conclusion] contradicts [Theobald's] allegation that a
mammal-bird intermediate would falsify universal common ancestry.
What was the point of offering Gardiner's conclusion if it is irrelevant to
the issue at hand? How can Gardiner's conclusion contradict the evolutionary
prediction when Camp admits that Gardiner's conclusion is irrelevant to the
evolutionary prediction? Is Dr. Theobald really not thinking clearly for
pointing out Mr. Camp's extensive habit of self-contradiction?
Nevertheless, Camp's off-point reply has even more flaws. The opinions of a
single scientist (or of a few scientists) are not necessarily representative of
scientific consensus. One can always find an "expert" who will agree with the
most ludicrous ideas (for an enormous amount of examples refer to QuackWatch). Camp's suggestion that
Gardiner's views on mammal-birds and common descent were in-line with scientific
consensus is incorrect. Such a claim is another example of Camp's use of the false appeal to
authority. Just because Gardiner remained committed to common ancestry does
not mean that his actions were logical or scientific. If Camp does not think
that Gardiner's views were representative of scientific consensus then Camp's
point is still unsound -- scientific consensus is what judges the impact of new
discoveries and evidence for scientific theories, not renegade scientists. In
this case, scientific consensus certainly realized the dangerous consequences of
Gardiner's analysis for common descent. That is why T. S. Kemp and Barry Cox
wrote what they did, as quoted above. That is why a slew of researchers quickly
demonstrated exactly where Gardiner's analysis went wrong and published the
et al. 1988; Hopson
1991; Kemp 1988;
Please note that, when considering "scientific consensus" in this debate, it
is unnecessary to assume that consensus is correct. The point is not that
consensus is somehow always right; the point is that it is invalid to draw
general conclusions from an exception. Doing so would be a fallacy of accident.
Furthermore, it is illogical to blithely assume that an "expert" correctly
judges an issue in his field. Doing so would be a false appeal to
authority. For example, it is unfair to maintain that Christianity condones
pedophilia simply because some Catholic priests have seemingly reconciled the
two. It is invalid to maintain that American Protestantism considers suicide as
acceptable behavior simply because of Jim Jones (an ordained
minister in the Christian Churches/Disciples of Christ) and the Peoples Temple.
It is incorrect to conclude that modern astrophysics is consistent with an
earth-centered universe (geocentrism) simply because Gerardus D. Bouw (Ph.D.
Astronomy, 1973, Case Western Reserve University) maintains that position. It is
untrue that the United States Federal judicial system considers the 14th
Amendment to the Constitution to be unconstitutional and invalid, even though
Judge Lander H. Perez (Louisiana) has submitted a statement to
Congress claiming such. Likewise, it is invalid to conclude that modern
evolutionary theory is consistent with mammal-birds, simply because of Brian
Gardiner's proposition. (Note: there is no other connection implied
between any of these examples besides the fact that they are extreme instances
of a logical fallacy).
The view promulgated by Gardiner was an extremely marginal one in the
scientific community (to my knowledge there are only three scientists on record
who supported it, including Gardiner). If the majority of the scientific
community had embraced the idea that mammals and birds are closely related, or
even admitted that it was reconcilable with current evolutionary biology, Camp
might have a defensible point about the reliability of the consensus phylogeny
(which is not the point at hand, in any case). In contrast, the mammal-bird
clade was considered "by the great majority of vertebrate biologists" to be
"outrageous" (in Kemp's words), and irreconcilable with contemporary
evolutionary biology (according to Cox, writing in Nature's News and
Views column, which is carefully selected and widely regarded to represent
scientific consensus on important developments). In spite of the opinions of the
few, scientific consensus maintains that mammal-bird intermediates are
impossible on our earth. This conclusion is all the stronger in light of the
aftermath of the Gardiner controversy.
Recall that Camp stated: "The ease with which this precise adjustment could
occur was illustrated two decades ago [by Brian Gardiner's cladistic analysis]."
That "precise adjustment," the switch from predicting reptile-bird intermediates
to predicting mammal-bird intermediates, occurred with ease for Gardiner. It did
not occur with ease for the scientific consensus, which is where scientific
theories are weighed, tested, confirmed, and falsified. Thus Camp's point
stumbles into self-contradiction: mammal-birds were not simultaneously
contentious and also accommodated with "ease," "without skipping a beat." Camp's
reply, therefore, is utterly without merit on several levels: it misses the mark
(by Camp's own admission) and it is logically flawed.
Additionally, calling it a "misguided attack" on his person, Camp has denied
that he misrepresented the Gardiner controversy:
The accusation that I misrepresented the controversy is based on the
false premise that I claimed Gardiner's theory gained general acceptance
in the scientific community and that it did so with ease. I claimed
This is false. Recall Camp's original claim:
Should a strikingly birdlike mammal be discovered, the standard tree
simply would be modified to accommodate the new creature, after
wrangling over its placement in the schema.
The ease with which this precise adjustment could occur was
illustrated two decades ago, when "[t]he reality of the 'mammal-bird,' a
hypothetical common ancestor of birds and mammals, [was] a contentious
issue in modern systematics."
The only way the standard phylogenetic tree would be modified is for
scientific consensus to accept the modification. That is why the standard tree
is called "standard." The standard tree is by definition the consensus
phylogeny. It is not called "Gardiner's phylogenetic tree." Thus, Camp indeed
claimed that Gardiner's hypothesis must have gained acceptance in the scientific
community; otherwise, the standard tree could not be adjusted or modified, as
Camp claims it was. Additionally, Camp claimed that this adjustment to the
standard tree occurred with "ease." In spite of Camp's protestations, it is
clear that he did indeed misrepresent the scientific controversy, since the
standard tree was not modified or adjusted due to the Gardiner controversy.
Another False Analogy
Of course, the discovery of a strikingly birdlike mammal would not
necessarily force a shift in thinking about the relationship of mammals
and birds (a placing of their branches next to each other). The birdlike
features could be attributed to convergent evolution. Many organisms are
believed by evolutionists to have evolved similar traits independently.
... If the mammal's birdlike traits were judged to be the result of
convergent evolution, the species would be shown on the phylogenetic
tree as a subset or side branch of mammals that was unrelated to birds.
Camp's point is true, but only for limited, trivial cases. Convergence is
more likely the less complex the trait. However, for very complex traits, true
structural convergence is essentially impossible in the context of common
descent and gradualism. For instance, independent evolution of bird flight
feathers is widely considered to be out of the realm of possibility. Camp gives
an example of possible convergence in an attempt to support his above
(In fact, some experts believe that the birdlike features of
dromaeosaurids, the dinosaurs considered by most experts to be the
sister group to birds, arose independently rather than by inheritance
from the ancestor of birds.)
Though thought unlikely by most paleontologists, such convergence is
possible, since the "bird-like" features of dromaeosaurids are in most cases
very subtle. The "experts" to which Camp refers here are Alan Feduccia and a few
other like-minded biologists. They maintain a minority opinion that
dromaeosaurids and birds are both independent descendents of thecodonts
(thecodonts are primitive dinosaur-like reptiles). In any case, dromaeosaurids
are much more similar to thecodonts than they are to modern birds. Thus,
Feduccia's suggestion of convergence is not so radical, even though the most
parsimonious hypothesis is that birds are the descendents of dromaeosaurids,
which in turn are the descendents of thecodonts. In contrast, the claim that a
mammal independently evolved bird flight feathers is extremely radical from an
evolutionary perspective. Camp's example of possible convergence does nothing to
support his erroneous opinion that evolutionary biology could easily accept
strikingly bird-like mammals.
More Distortion of Science
|The shift in thinking over the last 30 years about the relationship
of dinosaurs and birds is an example of a generally accepted
phylogenetic adjustment, albeit at a lower taxonomic level. From the
publication of Gerhard Heilmann's The Origin of Birds in 1926, it
was a matter of textbook orthodoxy that birds were more closely related
to thecodonts (an order of reptiles) than to theropods (a suborder of a
different order of reptiles). Thus, the discovery in 1964 of the
birdlike theropod Deinonychus was contrary to phylogenetic
expectations. Today, however, the standard phylogeny shows birds more
closely related to theropods than to thecodonts.
Camp's claim that "the discovery in 1964 of the birdlike theropod
Deinonychus was contrary to phylogenetic expectations" is false and does
not represent the true status of the scientific situation. As with the Gardiner
cladistic analysis, Camp misrepresents the true situation in order to make a
fallacious point. Coelurosaurs are theropods, and Deinonychus (the
"surprise" mentioned by Camp above) is a coelurosaur. Here are Gerhard
Heilmann's statements about bird origins from The Origin of Birds:
"On turning from the clumsy Predentates to the Coelurosaurs, we meet with
quite a different type; ... Hollow bones of very light structure, exceedingly
long hind-limbs with strong elongate metatarsals and a "hind-toe," a long,
narrow hand, a long tail and a long neck, large orbits and ventral ribs -- these
are bird-features immediately conspicuous." (Heilmann
1926, p. 165-166)
"... the striking points of similarity between Coelurosaurs and birds
pertained to nearly all the parts of the skeleton ... From this it would seem
rather obvious that it is amongst the Coelurosaurs that we are to look for the
bird ancestor. And yet, this would be too rash, for the very fact that
clavicles are wanting would in itself be sufficient to prove that these
saurians could not possibly be the ancestors of birds. ... We have therefore
reasons to hope that in a group of reptiles closely akin to the Coelurosaurs
we shall be able to find an animal wholly without the shortcomings here
indicated for a bird ancestor [i.e. the lack of clavicles]." (Heilmann
1926, p. 183-184)
Thus, the discovery of a bird-like theropod, the coelurosaur
Deinonychus, was clearly anticipated by Heilmann, since Heilmann already
considered coelurosaurs and other theropods to be quite bird-like. It's
bird-like nature was no surprise. Deinonychus is a coelurosaur; many
coelurosaurs had been known before 19644. Coelurosaurs were well-known to be strikingly bird-like
in many respects, as the Heilmann quotes above demonstrate unequivocally.
Thomas. H. Huxley had noted many of the close similarities between theropods
(including coelurosaurs) in the mid-19th century (Huxley
1870a), as had many other prominent paleontologists in the early 20th
1991, p. 437-447). Heilmann had reservations about theropods as bird
ancestors only because, at the time, theropods were not known to have clavicles
(a weak argument, of course, since it is based upon negative evidence -- it is now
known that clavicles fossilize poorly). Subsequent findings have established
that many theropods indeed have clavicles, such as Segisaurus, Velociraptor,
Euparkeria, Ingenia, Ornithosuchus, Oviraptor, Saltoposuchus, and
et al. 1990; Bryant
and Russel 1993). Some of these dinosaurs even have true furculae
(wishbones), a character once thought to be only found in birds.
Furthermore, it was Thomas H. Huxley who originated the hypothesis of the
theropod ancestry of birds all the way back in 1868 (Huxley
1868, p. 74).
The resurrection of the theropod ancestry hypothesis was initiated by J. H.
Ostrom in 1973, based upon his re-evaluation of the similarities between
Archaeopteryx and coelurosaurs (Ostrom
1973). Ostrom listed 21 specific shared derived characters between
Archaeopteryx and coelurosaurs as a taxonomic group (not just
Deinonychus) which had mostly been overlooked throughout the years. The
discovery of the bird-like coelurosaur Deinonychus in 1964 (first
described in Ostrom 1969) was further support for the theropod ancestry
hypothesis, but it was not a surprise that "was contrary to phylogenetic
expectations" -- it was directly in-line with contemporary phylogenetic
expectations. In reality, in 1964 the hypothesis that birds were descendents of
thecodonts was thought most likely, yet whether theropods were the intermediates
between thecodonts and birds was still an open question lacking any firm
supporting evidence either for or against (Bock 1969;
1996, p. 55-56; Witmer
1991, p. 437-447). Today, with the increased knowledge given by the
acquisition of many more fossils, and with the use of rigorously developed
cladistic techniques, birds are still thought to be the descendents of
certain thecodonts (or more correctly, of archosauromorphs, which are a
well-defined class of thecodonts -- "thecodont" is an outdated, grab-bag term which
is no longer used in the modern paleontological literature). Ostrom specifically
postulated a "thecodont-coelurosaur-Archaeopteryx-Aves phylogeny" (Ostrom
1973). Birds are descended from "thecodonts" via theropods.
Furthermore, Camp claims that, based on Heilmann's analysis, "it was a matter
of textbook orthodoxy that birds were more closely related to thecodonts ...
than to theropods" -- a statement which, strictly, is incorrect. Heilmann only
thought that coelurosaurs were not bird ancestors, and he thought it
likely that thecodonts, as a group, were bird ancestors. That does not
mean that birds are necessarily more closely related to thecodonts than to
theropods (or coelurosaurs). For instance, are you more closely related to your
siblings or to your great great great great grandfather? Of course, you are much
more closely related to your siblings -- yet they are not your ancestors (siblings
share half their DNA on average, whereas an individual and her great great great
great grandfather share only 1/64th of their genes). Likewise, birds
could be more closely related to coelurosaurs than thecodonts, while
simultaneously being the descendants of thecodonts but not of coelurosaurs. In
fact, this is likely what Heilmann thought, as he says:
"We have therefore reasons to hope that in a group of reptiles closely akin
to the Coelurosaurs we shall be able to find an animal wholly without the
shortcomings here indicated for a bird ancestor. Such a group is possibly the
Pseudosuchians [Pseudosuchians are 'thecodonts'] ..." (Heilmann
1926, p. 183-184)
More Misunderstanding of the Scientific Method, and Another
Back to Camp's criticism of the prediction of intermediate/transitional
The assertion that all fossilized animals conform to the standard
phylogenetic tree is unprovable, because one can never be sure that all
fossilized animals have been discovered.
Camp is clearly correct, but this is certainly not a problem. Camp has
pinpointed the very reason why this prediction is falsifiable and thus
scientific. The assertion that all fossilized animals conform to the standard
phylogenetic tree is unprovable, yes, like all scientific statements -- but it is
relatively simple to prove this assertion false. Which, by the way, is the
essence of falsifiability.
Interestingly, this turns out to be yet another instance where Camp
contradicts himself. At the end of his criticism of prediction
15, Camp writes this non sequitur:
The suggestion that universal common ancestry would be falsified by
"the discovery of a mammal without crossed gastrointestinal and
respiratory tracts, or a reptile or mammal without blindspots in its
eyes" is incorrect. It is another example of taking what is known not to
exist and claiming that evolution predicts it could not exist.
In one instance Camp (correctly) asserts that "one can never be sure that all
[organisms] have been discovered," and that, therefore, we can never prove a
given prediction of common descent about organisms. Later, when it is more
convenient to take the opposite stance, Camp (incorrectly) asserts that a
prediction of common descent is not really a prediction, since certain features
of organisms are already "known not to exist." How can we know that all mammals
and reptiles have crossed gastrointestinal tracts and blindspots if we cannot be
sure that we have discovered all mammals and reptiles? We can't. We can never be
certain of what exists with incomplete knowledge of the world, and this is
precisely why scientific predictions, like the predictions of common descent,
are testable, confirmable, and falsifiable.
But more importantly, the premise [that all fossilized animals
conform to the standard phylogenetic tree] turns out to be merely a
restatement of the claim of nested hierarchy. It adds nothing to the
case for common ancestry.
To the contrary, it is not simply a restatement of the nested hierarchy. The
"nested hierarchy" statement, given in prediction
2, is that modern organisms should conform to a nested hierarchy if common
descent is true. It is tested with modern species by zoologists, botanists, etc.
3 concerns the morphologies of organisms that existed in the past. It is
tested with fossils by paleontologists. In principle, prediction 2 could pass,
while prediction 3 could fail, or vice versa. Therefore, they are not the same.
Both predictions add to the case for common ancestry, since they are
independently tested and confirmed.
|... according to the definition of "intermediate" given in the
article, dromaeosaurids are not reptile-bird intermediates and
synapsids are not reptile-mammal intermediates. An "intermediate
form" is defined as "[a] fossil or modern species that displays
characters definitive of two or more different taxa" (emphasis
supplied). Dromaeosaurids do not display characters that are
definitive of both reptiles and birds (which is why they are not
considered birds), and synapsids do not display characters that are
definitive of both reptiles and mammals (which is why they are
not considered mammals). |
Camp is needlessly splitting hairs over terminology, while missing the point.
The word "definitive" is not a technical phylogenetic term, and it is not
intended to mean "unique" (in cladistic terminology such a "definitive
character" would be equivalent to a synapomorphy, but not always an
autapomorphy). Dromaeosaurs share many definitive characters with birds, such as
a furcula, a retroverted pubis, very long forelimbs, pneumatic (hollow) bones,
and a relatively large brain. Before dromaeosaurs were found, birds were the
only organisms that had many of these characters (like the furcula).
Dromaeosaurs also share many definitive characters with reptiles, such as teeth,
free articulating trunk vertebrae, a long tail with free vertebrae (no
pygostyle), less than six sacral vertebrae, unfused metacarpals, unfused
metatarsals, and gastralia. As listed above, dromaeosaurs share many characters
with birds, but they also lack many unique characters that birds have (such as
wings) -- so they are not birds. Dromaeosaurs are indeed intermediates between
birds and reptiles (especially dinosaurs) according to the given definition, and
similarly, synapsids are indeed intermediates between mammals and reptiles.
In footnote 13, Camp reiterates this error, plus making a few new ones:
Dromaeosaurids are considered a sister group to birds, meaning they
are believed to have shared with birds a most recent common ancestor.
They are not believed to have been in the actual lineage of birds. In
fact, they possess certain specializations, such as the stiffened tail,
that make them ill suited as ancestors. Of course, the presumed common
ancestor of birds and dromaeosaurids is thought to have been quite
dromaeosaurid-like. As already noted, dromaeosaurids do not qualify as
reptile-bird intermediates according to Dr. Theobald's definition.
Camp's concern about "actual lineage" is another misleading red herring and
is addressed in the next section. The statement that the stiffened tail makes
dromaeosaurids "ill suited" as bird ancestors is ridiculous; birds have
extremely stiffened tails (i.e. the pygostyle). Dromaeosaurs indeed have
specialized structures that are not likely to be found in bird ancestors, but
the stiffened tail itself is not one. The pertinent derived structures are found
on the tails of Dromaeosaurs. The stiffened tails of Dromaeosaurs have
specialized rod-like extensions of the vertebral zygapophyses which are not
found in the stiffened tails of birds.
Misrepresentation of Evolutionary Theory
|The assertions that there are "no morphological gaps" in the alleged
dinosaur-to-bird transition and that there is an "exquisitely complete
series of fossils" for the alleged reptile-to-mammal transition are
debatable, to say the least. I have elsewhere tried to point out some of
the limitations of those claims (see, "On the Alleged Dinosaurian
Ancestry of Birds" and "Reappraising the Crown
A detailed criticism of the two articles cited above will not be given here.
However, I will note that both criticisms boil down to two main points: (1) that
some transitional fossils are more derived than would be required for ancestors,
and (2) that some transitional fossils are not in perfect chronological order
relative to their cladistic rank. Neither point carries any weight as evidence
against common descent, for the simple reason that common descent does not
predict either (1) that transitional fossils are ancestors, or (2) that
transitional fossils should be in perfect chronological order relative to their
cladistic rank. If common descent does not make these claims, then observations
that contradict these claims cannot be evidence against common descent.
Point (2), concerning the chronological order of transitional forms, is dealt
with in the next section covering Prediction 5.
For point (1), as was stated concerning intermediate/transitional forms in the
4 and prediction
"A subtle, yet important point is that a strict cladistic evolutionary
interpretation precludes the possibility of identifying true ancestors; only
intermediates or transitionals can be positively identified. (For the purposes
of this article, transitionals and intermediates are considered synonymous.)
The only incontrovertible evidence for an ancestor/descendant relationship is
the observation of a birth; clearly this is normally rather improbable in the
fossil record. Intermediates are not necessarily the same as the exact
predicted ancestors; in fact, it is rather unlikely that they would be the
same. Simply due to probability considerations, the intermediates that we find
will most likely not be the true ancestor of any modern species, but will be
closely related to the predicted common ancestor. The minor implication
concerning fossil intermediates is that the intermediates we do find will
likely have additional derived characters besides the primitive characters
that identified them as intermediates. Because of these considerations, when a
new and important intermediate fossil species is discovered, paleontologists
will usually note that the transitional species under study is probably not an
ancestor, but rather is an evolutionary 'side-branch.'"
"... given what we know of modern species dynamics and recent extinction
rates, we know that the majority of organisms will eventually go extinct (Diamond
1992, ch. 12; Futuyma
1998, pp. 722-723). By extrapolation, the majority of past organisms also
have gone extinct. Thus, we should reasonably expect that the predicted common
ancestors had many other descendants and relatives that did not leave
descendants which survive today. In short, we predict that the majority of
fossil species that we find should not be the actual common ancestors of
modern species, but rather they should be related organisms that eventually
ended in extinction."
To restate -- common descent predicts that we may find transitional forms, but
transitional forms are not necessarily the same as common ancestors. Presumably,
Mr. Camp does understand this aspect of modern evolutionary theory but
has chosen to misrepresent it, as he has written this elsewhere:
As for the concept of "transitional forms" in general, the term
originally meant a creature that was part of the evolutionary transition
from species A to species D, so it was necessarily tied to lineage. When
evolutionists came up empty on that score, they changed the definition.
(This shift was still in process in 1984 when Cracraft wrote, "Part of
the confusion apparent *in the scientific literature* I suggest, stems
from the definition of 'transitional form.'") They now claim as a
"transitional form" any creature that is stratigraphically and
morphologically between any two taxa, without any regard for whether the
particular species represent a lineage. (And they sometimes take
creatures that are NOT stratigraphically intermediate and simply assume
they must have been.) This is a useful PR strategy for evolutionists
because whenever John Q. Public hears "transitional form," he still
In other words, Camp understands that common descent, at least in its modern
incarnation, does not predict that transitional forms are necessarily common
However, Camp nevertheless persists in arguing that
fossils which are transitional, yet have other derived characters that exclude
them as ancestors, are problematic for common descent. He persists in making
this misleading argument in the two articles cited above and in his critique of
the "29 Evidences," as well as in The Overselling of Whale
Evolution (all updated as recently as March 11, 2002). Furthermore, Camp
mistakenly claims that transitional form originally meant something other than
it does now, and that evolutionary biologists were compelled to adjust the
definition due to conflicting evidence (a position apparently borrowed from
Walter ReMine, e.g. ReMine 1993, p. 294-296, 414-415). Both Camp and ReMine are
incorrect; evolutionary biologists have not "changed the definition," nor have
they changed the relevant prediction. First, the definition is easily and
naturally derived from a phylogenetic tree and, second, Charles Darwin used the
modern definition in The Origin of Species in 1859 when he first proposed
the modern theory of common descent and first introduced phylogenetic trees to
the scientific world. The following quotes illustrate this point quite clearly:
... we ought to find in nature, not the actual transitional gradations by
which each complex instinct has been acquired -- for these could be found only in
the lineal ancestors of each species -- but we ought to find in the collateral
lines of descent some evidence of such gradations; or we ought at least to be
able to show that gradations of some kind are possible; and this we certainly
can do. (Darwin
1872, p. 320)
Referring to his famous figure,
It is worth while to reflect for a moment on the character of the new
species F14, which is supposed not to have diverged much in character, but to
have retained the form of (F), either unaltered or altered only in a slight
degree. In this case its affinities to the other fourteen new species will be
of a curious and circuitous nature. Being descended from a form that stood
between the parent-species (A) and (I), now supposed to be extinct and
unknown, it will be in some degree intermediate in character between the two
groups descended from these two species. But as these two groups have gone on
diverging in character from the type of their parents, the new species (F14)
will not be directly intermediate between them, but rather between types of
the two groups; and every naturalist will be able to call such cases before
his mind. (Darwin
1872, p. 157)
... the diagram throws light on the affinities of extinct beings, which,
though generally belonging to the same orders, families, or genera, with those
now living, yet are often, in some degree, intermediate in character between
existing groups; and we can understand this fact, for the extinct species
lived at various remote epochs when the branching lines of descent had
diverged less. (Darwin
1872, p. 158)
Supposing B and C to be two species, and a third, A, to be found in an
older and underlying bed ... A might be the actual progenitor of B and C, and
yet would not necessarily be strictly intermediate between them in all
respects. So that we might obtain the parent-species and its several modified
descendants from the lower and upper beds of the same formation, and unless we
obtained numerous transitional gradations, we should not recognize their blood
relationship, and should consequently rank them as distinct species. (Darwin
1872, p. 426)
More relevant evidence is given from the early evolutionary biologist, Thomas
Every fossil which takes an intermediate place between forms of life
already known, may be said, so far as it is intermediate, to be evidence in
favour of evolution, inasmuch as it shows a possible road by which evolution
may have taken place. ... Suppose A, B, C to be three forms, while B is
intermediate in structure between A and C. Then the doctrine of evolution
offers four possible alternatives. A may have become C by way of B; or C may
have become A by way of B; or A and C may be independent modifications of B;
or A, B, and C may be independent modifications of some unknown D. ... it is
always probable that one may not hit upon the exact line of filiation, and, in
dealing with fossils, may mistake uncles and nephews for fathers and sons.
I think it necessary to distinguish between [...] classes of intermediate
forms, as intercalary types and linear types. When I apply the former term, I
merely mean to say that as a matter of fact, the form B, so named, is
intermediate between the others, in the sense in which the
Anoplotherium is intermediate between the Pigs and the
Ruminants -- without either affirming, or denying, any direct genetic relation
between the three forms involved. When I apply the latter term, on the other
hand, I mean to express the opinion that the forms A, B, and C constitute a
line of descent, and that B is thus part of the lineage of C. (Huxley
1870b, p. 348-350)
From a popular introductory evolutionary college textbook from the '50s and
[Intermediate form] always included the idea of a form standing midway
between two groups of animals now clearly separate from each other. (Moody
1953, p. 188)
From a modern introductory evolutionary textbook:
transitional form A species that exhibits traits common to ancestral
and derived groups, especially when the groups are sharply differentiated. (Freeman
and Herron 2001, p. 686)
From all these quotes it is evident that early evolutionary biologists did
not necessarily equate "intermediate" with "ancestor," and that intermediates do
not need to be part of a direct genealogical lineage. This has been clear from
the outset. Even in the cases where intermediates are ancestors, Darwin
explained that ancestors may have derived characters which were subsequently
lost in their descendents. Finally, neither Darwin nor Huxley expected that we
should necessarily identify common ancestors, but rather that we should find
intermediates. These remain the modern evolutionary views (they are now
most often couched in cladistic terminology).
Camp complains that "This is a useful PR strategy for evolutionists because
whenever John Q. Public hears 'transitional form,' he still thinks 'lineage.'"
This gripe is humorous, since "transitional form" is a scientific term, and as
such should be defined by scientists as they wish. It's as if Camp were
complaining because in Newtonian physics the product of mass and acceleration is
called a "force," and that "force" is inappropriate because it sounds too
"mystical" to the layperson. Besides, if evolutionary biologists wanted to
convey "lineage," the most obvious tact would be to use the term "ancestors" in
place of "transitional forms." In spite of Camp's bias, "transitional form" is a
perfectly accurate description which has no genealogical connotations.
Consequently, since the terms "intermediate" and "transitional" have been
defined since the genesis of evolutionary theory, Mr. Camp has no justification
in perpetuating misleading arguments and statements concerning the proper
evolutionary definitions of these terms and the relevant predictions of common
descent. In doing so, Camp joins the ranks of other creationist
anti-evolutionists who knowingly reinforce the widespread, yet incorrect, lay
public perception that transitional forms are always common ancestors.
An Attack on Science
Mr. Camp concludes this section with a veiled attack upon the scientific
But even if one granted that reptiles evolved into a bird and a
mammal, that would not establish that reptiles and all other organisms
descended from a common ancestor, which is the proposition being argued.
The difference between a bacterium and a reptile, not to mention the
other organisms, is considerably greater than the difference between a
reptile and a bird or a reptile and a mammal. So the fact a reptile
could evolve into a bird or a mammal would not mean that a bacterium
could evolve into a reptile and everything else. In fact, granting that
reptiles evolved into a bird and a mammal would not even establish that
all birds and all mammals descended from a reptile. That would be an
In this paragraph Camp is criticizing the fundamental scientific practice of
extrapolation. Extrapolation underlies all of science; without extrapolation, we
could not make any scientific conclusions or predictions. When we sent the
Surveyor 1 spacecraft to the moon in 1966, we assumed that
Newton's laws of physics operated on the moon, just as they operate on the
earth. We assumed this even though we had never sent anything to the
moon's surface before. And, of course, we were correct -- so correct that two years
later we entrusted the lives of several men to our assumption. Our assumption
was the result of extrapolating from what was known (earth bound physics) to
what was unknown (lunar physics). Furthermore, we assume that Newton's laws of
physics hold on Neptune and Uranus, even though we have never explored the
surfaces of those planets. Likewise, once we have established that certain
reptiles have evolved into birds and mammals, we can easily assume that all
birds and mammals are descendents of reptiles. We can assume this because it is
trivial to conclude that all birds are related by common descent. If a reptile
can evolve into a bird then certainly a bird can evolve into another bird. This
particular extrapolation should not be controversial for Mr. Camp, since
creationists of all stripes generally believe that all birds are modified
descendents of an original created bird "kind." Once we have established that
something like a bird can evolve from a reptile, we assume that similar things
happened with other species and in other lineages.
Camp has replied to this:
According to Dr. Theobald, I am here denying the legitimacy of the
principle of extrapolation and thus depriving science of its ability to
make any conclusions or predictions. All I am doing is pointing out the
difference between what is extrapolated or assumed and what is proved.
Once again we find evidence of Camp's misunderstanding of basic science and
the scientific method. Camp errs in claiming that there is a difference between
what is extrapolated or assumed and what is proven. In science, nothing can be
proven. The reason nothing can be proven is very simple -- all scientific
conclusions rely upon the fallacy of affirming the
consequent, and in doing so they rely upon inductive extrapolation. In
contrast, a theory conceivably could be shown to be false by using a valid modus tollens
argument. These issues were the foundation behind Sir Karl Popper's reasoning
and his falsifiability criterion for the scientific method. In the end, though,
even falsification is flawed, as the premises of any modus tollens
argument cannot be proven since their validity is also established by affirming
the consequent. Mr. Camp surely is aware of this, as he appears to be
well-versed in logic. To clarify the import of this scientific dilemma, consider
the following example provided by Mr. Camp in his discussion of extrapolation:
Earth-bound physics can be extrapolated to the solar system and
universe, but that would not mean the extrapolation was justified. That
would have to be demonstrated by evidence (which it was prior to the
moon landing in 1969).
Camp thinks that it was valid to assume that the laws of physics worked on
the moon like they do on the earth, because he thinks this particular
extrapolation was proven prior to the 1969 moon landing. The logic goes
something like this:
Premise 1: If laws of earth-bound physics are obeyed on the moon, then
spacecraft which we send there will behave as we predict, based upon earth-bound
Premise 2: Our spacecraft behaved as we predicted (such as the
Surveyor 1 spacecraft in 1966).
Conclusion: The laws of earth-bound physics are obeyed on the moon.
This argument is a classic example of affirming the consequent, a fallacy of
propositional logic. In the above argument, we have extrapolated from one event
(the Surveyor 1 spacecraft) to a generality. For some reason, Camp thinks
an extrapolation here is "demonstrated by the evidence," even though it is
logically fallacious, but he does not allow extrapolation in biology. As
explained earlier, in his attack on extrapolation Camp is attacking all of
science. In fact, if we deny science the right to extrapolation, we deprive
science of the ability to make predictions and conclusions. If we allow
extrapolation, we simply cannot claim that scientific conclusions are proven.
This does not mean, however, that science cannot approximate reality and make
useful predictions and explanations, as it obviously does. In practice,
scientists use probability and statistics to quantify the degree of support that
evidence provides for a given hypothesis or theory. In sum, since nothing can be
proven in science, and all is extrapolation, Camp is not "pointing out the
difference between what is extrapolated or assumed and what is proved" -- he is
attacking the scientific practice of extrapolation, plain and simple. Mr. Camp's
philosophical and theological bias allows him to ignore scientific extrapolation
unless the conclusions conflict with his preconceptions.
Camp ends here on a strange note by adhering to only birds, reptiles, and
mammals. The prediction being criticized was the general prediction from common
descent of transitional forms. The bird-reptile transitional forms (such as
Archaeopteryx and the various wingless feathered dinosaurs recently found
in China) that Camp mentions are only a small minority of the numerous
transitional forms found in the fossil record. All of these intermediates
linking the grand swath of living and extinct organisms certainly do offer
strong support for universal common descent when taken as a whole.
Prediction 5: Chronological order of predicted common
More Misrepresentation of Evolutionary Theory, and Another
Camp correctly restates the prediction and then begins his criticism in
|There is nothing about the hypothesis of universal common ancestry
that requires organisms to have descended in the pattern depicted in the
standard phylogeny. ... A phylogeny is simply a depiction of the order
in which evolutionists believe taxa arose, not the order in which they
were required to arise. |
Camp has it backwards. Cladistic phylogenies are built based upon morphology.
The order in which organisms arose is a deduction from a phylogeny. Thus,
whenever we have a well-supported phylogeny, the order in which organisms are
required to have arisen is firmly predicted, based upon that phylogeny. Camp
directly contradicts himself in the next paragraph:
... ancestral taxa must have existed before any taxa that descended
from them ...
Yes, and that is exactly why a phylogeny predicts the relative order in which
taxa have arisen during evolution.
Camp has responded to this:
|... one cannot predict from universal common ancestry that
intermediates will appear as reflected in the standard phylogeny. That
prediction must be rooted elsewhere than in the bare hypothesis of
universal common ancestry. ... the expectation that organisms will
appear in a particular order is not a deduction from universal
common ancestry; it arises from a phylogeny. Thus, the hypothesis of
universal common ancestry would not be proven false by the discovery of
a fossil "intermediate" out of the order reflected in the standard
Here Camp's words are still confused and again misrepresent evolutionary
theory. The standard phylogeny is the rigorous scientific depiction of universal
common descent; they are one and the same. The reasoning is very simple: common
descent is the hypothesis that all living species are genealogically related,
and everything that is related has a genealogy. A genealogy of species is a
phylogeny, and thus the genealogy of all species is the standard phylogeny.
Since organisms must have arisen in the order depicted in a phylogeny, the order
of evolution of all organisms is a deduction from common descent.
To reveal the incorrectness of Camp's statements, let's construct an
analogous comment with Newton's Theory of Gravity (the universal Gravitational Inverse Square Law, GISL) replacing universal common
... one cannot predict from universal GISL that masses will accelerate as
reflected by the standard gravitational constant, G. That
prediction must be rooted elsewhere than in the bare hypothesis of universal
GISL. ... the expectation that masses will accelerate at a given rate is
not a deduction from universal GISL; it arises from a gravitational
constant. Thus, the hypothesis of universal GISL would not be proven false by
the discovery of a mass which does not accelerate as expected according to the
standard gravitational constant, G.
I hope it is clear that these statements are incorrect, as are the analogous
ones that Camp makes about common descent. The reason that these comments are
incorrect is because the standard gravitational constant G is the
rigorous scientific quantification of universal GISL, just like the standard
phylogeny is for common descent. If universal GISL is true, then all masses must
accelerate at rates consistent with the universal constant G. If
universal common descent is true, then all organisms must have arisen in the
order depicted in the standard phylogeny.
Failing to grasp the point, Dr. Theobald accuses me of contradicting
myself in the very next paragraph because I acknowledged the truism that
ancestors must have existed before descendants.
Camp contradicts himself because he fails to grasp the truism that the
standard phylogeny is equivalent to a specification of universal common descent
on our planet (just like the universal gravitational constant G
specifies the universal GISL in our universe).
Insufficient Knowledge of Evolutionary Methods and Data
... it remains possible for a proponent of common descent to assert
that select taxa appear in the fossil record contrary to the order in
which they came into existence.
Witness the fact dromaeosaurids, which are offered by Dr. Theobald as
"reptile-bird intermediates," first appear in the fossil record some 25
million years after the first fossil bird. ... Rather than
disqualifying dromaeosaurids in Dr. Theobald's eyes as "reptile-bird
intermediates," which he argues must appear in the order suggested by
the standard phylogeny, it is simply assumed that dromaeosaurids lived
tens of millions of years before there is any evidence of their
existence. (The ambiguity of "general chronological order"
prevents such nonconformities from falsifying the claim.)
The issue of "out-of-order" fossils has been addressed thoroughly in the
updated version of Prediction
5. If we consider the entire geological record of the earth, an uncertainty
of 25 million years is equivalent to less than 0.6% relative uncertainty. If we
consider only the fossil record of life, an error of 25 million years is
equivalent to, at most, a 1% relative uncertainty. Both values are overall quite
minor. In fact, we know empirically that the error inherent in the fossil record
is worse than that. For example, the coelacanth last appeared in the fossil
record 80 million years ago, yet it is alive today. Thus, arguing that certain
fossils are "out-of-order" by merely 25 million years is a meaningless argument.
It carries no scientific weight. In contrast, the finding that these fossils
were "out-of-order" by, say, 150 million years would be much more significant,
since the resolution of the fossil record is known to be better than that in
most cases (especially throughout the Mesozoic and Cenozoic).
The assertion that "The ambiguity of 'general chronological order'
prevents such nonconformities from falsifying the claim [of prediction 5]" is
incorrect. There are very well defined scientific statistical methods for
determining whether the chronological order of fossils generally matches
the order required by the consensus phylogenies. If stratigraphy generally
matches phylogeny, then there is a positive correlation between stratigraphic
position and phylogenetic rank. It is also possible to demonstrate that there is
either no correlation between phylogeny and stratigraphy or that there is an
anti-correlation. Demonstrating a statistically significant negative correlation
between the standard phylogenetic tree and the fossil sequence would be a firm
falsification of this basic macroevolutionary prediction. However, as detailed
5, there is overall a statistically significant positive correlation between
stratigraphy and phylogeny, which is a strong confirmation of the prediction
that "fossilized intermediates should appear in the correct general
chronological order based on the standard phylogenetic tree."
The fact synapsids appear before dromaeosaurids hardly constitutes
proof (confirms the "prediction") that "fossilized intermediates" appear
in the general chronological order indicated in the standard phylogeny.
They are only two data points.
True, but they were only given as representative examples, not as sole
"proof." Furthermore, these two data points are very well-supported
phylogenetically, and their temporal separation (~150 million years) is outside
the likely error of the fossil record.
But more importantly, one must bear in mind that Figure 1 is of
necessity a simplified and fragmentary phylogeny. The picture changes
significantly when the scope of inquiry is broadened. According to one
"[T]he correspondence between phylogeny and the fossil record is
not as strong as it might first seem. When the order of all kingdoms,
phyla and classes is compared with the most reasonable phylogenies,
over 95 percent of all the lines are not consistent with the order in
the fossil record." (Wise
1994, p. 225-226.)
Again, Camp is quite mistaken. The quote from Kurt Wise is supported by
opinion only, not by facts or by any published analysis of the data. In reality,
the more diverse the taxa that are included in the analysis, the stronger the
correlation between stratigraphy and phylogeny, and the more statistically
significant it becomes. For many relevant references, see the "Confirmation"
of Prediction 5.
Camp has replied:
That is true, but it does not alter the fact Wise performed the
analysis and reached the quoted conclusion.
Actually, we have no evidence that Wise performed the analysis. We can take
Wise's word for it (and in fact I do)3,
but most importantly we have no reason to believe that
Wise's analysis is correct. That is exactly why science is fundamentally
dependent upon peer review -- other scientists need to evaluate the data and double
check the methods and conclusions of any scientific analysis. It is quite common
for even respectable, intelligent, well-meaning scientists to make mistakes. As
might be expected, anti-evolutionists (especially the "scientific" creationists)
are not fond of peer review.
Dr. Theobald then gives the impression that Wise's conclusion is
contradicted by a dozen studies referenced in the "Confirmation" section
of Prediction 5 of his revised article. That, however, is incorrect.
In fact, that "impression" is quite correct, and it is based on numerous
published analyses from many different researchers.
None of those studies duplicated Wise's analysis. That is, they did
not compare the order of all kingdoms, phyla, and classes with their
most reasonable phylogenies. Rather, they took multiple cladograms of a
narrower range of taxa and compared them with the fossil record for
These statements are ludicrous. Wise's analysis has never been published; how
does Camp know what Wise did?
Moreover, the results are not as impressive as one might think from
Dr. Theobald's comments.
Camp then goes on to list specific data from some of the referenced published
papers which demonstrate a highly significant correlation between stratigraphic
order and phylogeny. Camp erroneously believes it is problematic that a minority
of single cladograms show no correlation with stratigraphic data. If this were
true of scientific theories, then the fact that smoking causes cancer would be
falsified, since many people who smoke do not develop cancer. But science does
not work that way. All physical processes involve stochastic (chance) elements,
and scientific results are evaluated statistically. Camp's argument is another
clear example of the fallacy of accident (or
more correctly, "converse
accident"). Camp conveniently omits the statistical analyses which
demonstrate exactly how impressive the total data really are.
For instance, Michael Benton and Rebecca Hitchin published a recent, greatly
expanded, and detailed stratigraphic analysis of 384 published cladograms of
various multicellular organisms (Benton
and Hitchin 1997). Using the three measures of congruence between the fossil
record and phylogeny mentioned by Camp (the RCI, GER, and SCI), these
researchers observed values "skewed so far from a normal distribution [i.e.
randomness] that they provide evidence for strong congruence of the two datasets
[fossils and cladograms]." The results were overall extremely statistically
significant (P < 0.0005), a result that is extremely impressive. With
his blatant anti-science bias, Camp might subjectively feel that these "results
are not as impressive as one might think," however, scientists use statistics as
an objective measure of "impressiveness." High statistical significance is
considered as strongly confirming the predictions of a theory (P ≤ 0.01); the
results from Benton and Hitchin's analyses are at least 500 times more
impressive than that. As the authors comment in their discussion:
"... the RCI and SCI metrics showed impressive left-skewing; the majority
of cladograms tested show good congruence between cladistic and stratigraphic
information. Cladists and stratigraphers may breathe easy: the cladistic
method appears, on the whole, to be finding phylogenies that may be close to
the true phylogeny of life, and the sequence of fossils in the rocks is not
misleading. ... it would be hard to explain why the independent evidence of
the stratigraphic occurrence of fossils and the patterns of cladograms should
show such striking levels of congruence if the fossil record and the
cladistic method were hopelessly misleading." (Benton
and Hitchin 1997, p. 889, emphasis added)
In sum, the chronological appearance of fossils in the fossil record
generally matches very well with the order required by the consensus phylogeny
of the major taxa. Although it was possible to falsify this prediction, this
prediction has been confirmed and offers strong support for the theory of common
Camp's criticism of Section 1 of the "29 Evidences" was nearly twice as long
as Section 1 itself; my response to Camp's criticism of Section 1 is nearly four
times as long as the original Section 1. The remaining four sections will have
to wait. None are difficult to rebut, except for the time and effort required.
As stated at the beginning of this rebuttal, Camp's critique is error-ridden in
various ways, and is plagued by this "host of intellectual sins" (in Camp's own
- Red herrings
- Two wrongs make a right
- Fallacies of accident
- Ignoratio elenchi
- Naive theological assumptions
- Insufficient knowledge of basic biology, molecular biology, biochemistry
- Misunderstanding of the scientific method
- Straw man arguments
- Forwarding of untestable competing "hypotheses"
- Mischaracterization of evolutionary theory
- Quoting out of context
- Fallacies of accent
- Distortion of scientific controversies
- Arguments from authority
- False analogies
Each of these resurfaces in the remaining four sections of the critique. As
demonstrated in even this limited rebuttal, Camp's criticism of the "29
Evidences" is without scientific merit.
Camp concludes his article with this claim for his motivation:
Dr. Theobald [is] certain that the evidence of nature points
ineluctably to the conclusion of universal common ancestry. I once
shared that opinion of history, but having shifted my point of view, I
find that the same evidence points to something entirely different.
What is this "something entirely different"? From the second sentence of
I believe the founding members of these groups [of organisms] were
created miraculously and separately by God.
There is good reason to be skeptical of the claim that Camp was led to this
conclusion by the "evidence of nature." Camp has written elsewhere that his
rejection of evolutionary theory is not based in scientific evidence, but rather
it is a result of a religious conviction to a literal interpretation of Genesis.
"[Scripture] cannot contain errors or falsehoods. Everything in it
must be true ... " (Camp
1999, p. 20-21)
"I sympathize with the desire to present Scripture as compatible with
current scientific orthodoxy, but the exegetical objections to this
theory strike me as insurmountable. ... All such interpretations strike
me as attempts to conform the Bible to conclusions drawn elsewhere ...
If the meaning of Scripture is distorted to fit scientific opinion, its
authority has been relinquished. ... This is not to deny that it is
difficult at present to harmonize some of the scientific data with a
recent-creation interpretation of Scripture." (Camp
1999, p. 42-43)
It is also difficult to reconcile Camp's statement that "I find that the same
evidence points to something entirely different" with "it is difficult at
present to harmonize some of the scientific data with a recent-creation
interpretation of Scripture."
Perhaps, then, even Mr. Camp agrees that his critique is not based in
Job hath spoken without knowledge, and his words were without
wisdom. -- Job 34:35
Then the Lord answered Job out of the whirlwind, and said,
"Who is this that darkeneth counsel by words without knowledge?
Gird up now thy loins like a man; for I will demand of thee, and
answer thou me. Where wast thou when I laid the foundations of the
earth? declare, if thou hast understanding."
"Hast thou entered into the springs of the sea? or hast thou
walked in the search of the depth?"
"Hast thou perceived the breadth of the earth? declare if thou
knowest it all."
"Where is the way where light dwelleth? and as for darkness,
where is the place thereof,"
"Hast thou entered into the treasures of the snow? or hast thou
seen the treasures of the hail,"
"Hath the rain a father? or who hath begotten the drops of dew?
Out of whose womb came the ice? and the hoary frost of heaven, who
hath gendered it?"
-- from Job 38
The Lord by wisdom hath founded the earth; by understanding hath
he established the heavens. -- Proverbs 3:19
The fear of the Lord is the beginning of knowledge: but fools
despise wisdom and instruction. -- Proverbs 1:7
Wisdom is the principal thing; therefore get wisdom: and with all
thy getting get understanding. -- Proverbs 3:7
1. As an aside, Camp has misplaced the above Denton quote. To be fair, Denton
made that remark in response to the controversial "molecular clock" hypothesis,
which is related though distinctly different from the observation of equal
molecular divergences between species. From his later comments, Camp evidently
does not understand this difference. The molecular clock hypothesis is the idea
that rates of evolution are constant throughout time. Rates could be extremely
variable yet result in equal genetic distance between two species
serendipitously. Conversely, rates could be very constant in specific lineages,
yet result in unequal genetic distances (if the rates are unequal between
lineages). Regardless, Denton is still confused on the subject, as he
uncritically assumes that absolute background mutation rates in yeast should be
"100,000 times greater than in a tree or a mammal ..." (Denton
1998, p. 291-292). This would only be true if DNA replication errors were
the primary source of mutations. However, there is currently little data
supporting this directly. Recent studies have indicated that other sources of
mutation are more important (Huttely
et al. 2000; Bohossian
et al. 2000; Kumar
and Subramanian 2002). All else equal, we expect that absolute background
mutation rates should be equivalent between species, and that is roughly what is
observed. Even if DNA replication errors are the primary cause of mutations,
from the most basic conclusions of neutral theory there are other reasons
(beyond the scope of this rebuttal) for why rates of protein evolution should be
relatively equal between organisms with very short or very long generation times
1993 and references therein -- this article gives the consensus explanation
which Denton claims does not exist, and it demonstrates that the evidence
supports this explanation). Back
2. Camp is incorrect here in his assessment that stratigraphy bears upon
whether an organism is considered a transitional form or not. A transitional
form is defined purely in terms of morphology, regardless of age. Additionally,
Camp's quote of Cracraft is horribly out-of-context due to the ellipses. The
quote originally read -- "Part of the confusion apparent in the scientific
literature and the religious writings of the creationists, I suggest, stems from
the definition of 'transitional form.'" (Cracraft
3. Kurt Wise is extremely honest, and, of all the "scientific creationists,"
Wise bears both the best credentials and the best of reputations. Wise has
admittedly relinquished all pretense of scientific objectivity, as he does not
trust science to accurately represent reality. Wise has written:
"Although there are scientific reasons for accepting a young earth, I am a
young-age creationist because that is my understanding of the Scripture. As I
shared with my professors years ago when I was in college, if all the evidence
in the universe turns against creationism, I would be the first to admit it,
but I would still be a creationist because that is what the Word of God seems
to indicate. Here I must stand." (Wise
As such, Wise holds certain "hypotheses" (including a very narrow and
theologically questionable interpretation of Scripture) which he will believe
even though all evidence indicates otherwise. Such statements, ostensibly coming
from a scientist practicing the scientific method which holds all conclusions as
provisional and open to further testing, certainly indicates that there is no
reason to trust the scientific validity of any unpublished, unreviewed
"analyses" performed by this man. In light of the fact that Mr. Camp is fond of
quoting "creation scientists" like Duane Gish, Lee Spetner, Walter ReMine, and
"John Woodmorappe," another honest statement by young-earth creationist Wise is
"Most creation science is garbage" (quoted in an interview in Hitt
Wise has expounded:
"This gets me in a lot of trouble with a lot of creationists, ... the
material that's out there is -- uh, I'll hold back and be nice -- garbage. It's
really atrocious" (quoted by Mayshark
4. Such as Ornithomimus antiquus, found in 1865, O. velox,
1890, O. edmontonicus, 1933, O. lonzeensis, 1903, O.
sedens, 1892, Paronychodon lacustris, 1876, Ornitholestes
hermanni, 1903, Proceratosaurus bradleyi, 1910, Compsognathus
longipes, 1859, Struthiomimus altus, 1902, Thecocoelurus
daviesi, 1888, Chirostenotes pergracilis, 1924, Oviraptor
philoceratops, 1924, Therizinosaurus cheloniformis, 1954,
Alectrosaurus olseni, 1933, Albertosaurus sarcophagus, 1905, A.
grandis, 1890, Tarbosaurus efremovi, 1955 T. bataar, 1955,
Tyrannosaurus rex, 1905, Velociraptor mongoliensis, 1924,
Dromaeosaurus albertensis, 1922, D. cristatus, 1876, D.
explanatus, 1876, and D. gracilis, 1888. Back
6. Camp has replied to my explanation about the constraint of gradualism in
considering valid evolutionary mechanisms. He claims that the case was
overstated due to the use of a particular word, "any". However, this criticism
is erroneous and is an example of the fallacy of accent:
... one must recall that Dr. Theobald claimed in his article to prove
universal common ancestry "independent of any explanatory
mechanism." ... The point, however, is that the requirement of
gradualness restricts the universe of mechanisms. So if one's argument
for common ancestry assumes gradualism, one is not arguing for common
ancestry "independent of any explanatory mechanism." Rather, one
is making an argument for common ancestry that is dependent on gradual
explanatory mechanisms. ... Rather than acknowledge that he overstated
his case, Dr. Theobald ignores his contradictory statements and blames
me for not knowing that he really meant to restrict the explanatory
mechanisms to gradual ones. If that was his intent, he should not have
claimed that he was arguing for common ancestry "independent of any
explanatory mechanism." He was trying to have his cake and eat it too.
The statement that "the evidence and the conclusion [of common descent] are
independent of any explanatory mechanism" was made on the very last page of the
article. By placing it there, I assumed that the reader had in fact read the
introduction and the rest of the article. It is clear Mr. Camp himself wrongly
assumes that "any" is equivalent to "all." Saying that common descent is
independent of any explanatory mechanism is not the same as saying that common
descent is independent of all possible explanatory mechanisms (see
definitions 1a, 2a, 2c, and 3b for any in the
Merriam-Webster Dictionary, or the first two definitions of any
in the Cambridge International Dictionary of English). Camp misleadingly places
emphasis upon the word "any." I did not emphasize the word "any" as Camp did
when he quoted my statement; this is an example of the fallacy of accent.
Even if one incorrectly interprets the somewhat ambiguous word "any" as "all,"
all mechanisms are not valid explanatory mechanisms. The gradualistic
restriction of explanatory mechanisms is and was explicitly made numerous times
throughout the "29 Evidences" (e.g. all of Part 3 is
devoted to the direct consequences of this concept -- note the quote at the
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