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Camp Answers Theobald

Reply to Theobald’s Response to Part 1 of Critique

By Ashby L. Camp Copyright 2002 by Ashby L.  Camp.  All rights reserved.

In “29 Evidences for Macroevolution,”^[1] Douglas Theobald asserted that the hypothesis of universal common ancestry had been proven scientifically because 29 falsifiable predictions of the hypothesis had been fulfilled.  I explained in my critique of his article why that is not the case.  Dr. Theobald has now posted a lengthy rejoinder to the first section of my critique, accusing me of devious tactics, widespread ignorance, and a host of intellectual sins.  I leave it to the reader to judge the fairness of those charges. 

Prediction 1:  The Fundamental Unity of Life

Dr. Theobald’s main argument under this section is that the hypothesis of universal common ancestry predicts that all creatures will have in common the structures and mechanisms that perform the following basic life functions: replication, information flow in continuity of kind, catalysis, and energy utilization (metabolism).  As I showed in the critique, that is not a falsifiable prediction of common ancestry. 

If different structures and mechanisms for basic life functions were discovered in creatures A and B, and if proponents of common ancestry admitted they could not imagine how both organisms could have descended from a conventionally assumed ancestor, they could still preserve their theory in one of two ways (or a combination thereof).  First, they could claim that the inability to imagine a chain of descent from such an ancestor is merely a function of our ignorance, a matter for further research.  In other words, they could treat it the same way Neo-Darwinists treat the inability to imagine the steps through which allegedly irreducibly complex structures and systems evolved. 

Second, they could take the difference between A and B as an indication that the common ancestor must have been different than is conventionally believed.  If, for example, one assumes that the universal common ancestor lacked DNA and RNA (per Shapiro) or that it was a crystalline clay organism (per Cairns-Smith), it opens new avenues of evolutionary imagination and speculation.  In an evolutionary framework, the claim that a hypothetical organism of unspecified traits gave rise to both A and B cannot be disproved.  So the claim that the discovery of creatures A and B would falsify the hypothesis of common ancestry is incorrect. 

Dr. Theobald accuses me of constructing a straw man because I said his argument was that the hypothesis of universal common ancestry predicts that all organisms will have one or more traits in common.  He claims that this summary phrasing weakens his argument by omitting the fact he specifies that the traits all organisms must have in common relate to the basic functions of life.  He then quotes “from the original prediction 1” to verify that his claim was more specific.  (In saying that he was quoting “from the original prediction 1,” Dr. Theobald may leave the casual reader with the false impression that those comments were not included in my paper.  The fact is that I quoted his alleged prediction in its entirety.)

Even if I had not quoted Dr. Theobald’s prediction in its entirety, 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, which is that an inference can be drawn about origins on the basis of similarities. 

Dr. Theobald next accuses me of confusing gradualism with the concept of evolutionary mechanism.  To appreciate what is going on here, one must recall that Dr. Theobald claimed in his article to prove universal common ancestry “independent of any explanatory mechanism.” He wrote that his proof did not depend on “whether Darwinism, Lamarckism, or something else is the true mechanism of evolutionary change or not” (emphasis supplied).  I pointed out that a bare claim of universal common ancestry, one that is independent of any mechanism of descent, is compatible with all mechanisms of descent, including divine direction. 

I noted in my critique (footnote 1) that Dr. Theobald contradicted his claim to argue for common ancestry without regard to any particular mechanism by including in his definition of macroevolution the requirement of gradualness.  He is now trying to deny that contradiction by arguing that gradualness is not a 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. 

It is in that context that I wrote:

Dr. Theobald understandably seeks to free the claim of universal common ancestry from the debate about the sufficiency of evolutionary mechanisms, particularly the debate about Neo-Darwinism.  It should not go unnoticed, however, that a bare claim of 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 ancestry. 

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.

Contrary to Dr. Theobald’s assertion, I do not “paradoxically” criticize the constraint of gradualism in footnote 1.  I point out that the constraint contradicts his claim to argue for common ancestry independent of any explanatory mechanism.  Nor am I wrong in saying that Dr. Theobald does not address the sufficiency of accumulated observable variation to account for universal common ancestry.  He speaks of observable variations, but he simply assumes they can be extrapolated across all biological divides. 

Dr. Theobald next charges me with presenting a red herring because I included in a quote from Walter ReMine a statement that evolution does not predict that life would arise only once on this planet.  The accusation is silly.  I state in the introduction that “Dr. Theobald does not address the origin of the first living thing,” and I state in the footnote accompanying ReMine’s quote that “Dr. Theobald assumes a single origin of life, so this comment is beyond the scope of his paper.” I also explain in the footnote that I included the comment “to provide context for the remainder of the quote.” I simply did not want the quote to begin with “Second, .  .  .”

Dr. Theobald accuses me (and, indirectly, Walter ReMine) of ignoring “the fundamentals of biology and the constraint of gradualism” in denying that common descent predicts biological universals.  He states:

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. 

When Neo-Darwinists are confronted with structures and systems that are alleged to be irreducibly complex, they scoff at the claim by appealing to the possibility of an undiscovered pathway through which such systems and structures could have been constructed incrementally.  A proponent of universal common ancestry could make the same argument regarding structures that perform basic life functions.  That is, he could say that just because we do not yet understand how viability could have been maintained during the incremental construction of those structures does not mean that the chain did not exist.  When one adds the option of varying the traits of the hypothetical ancestor, such as assuming that it possessed no organic molecules, the room for speculation is boundless. 

After offering an unhelpful analogy, Dr. Theobald says:

[G]iven the fact that we now know that all organisms studied to date, including bacteria and birds, have a very similar glycolysis metabolic pathway (or 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 glycolysis metabolic pathway (or genetic code). 

The point is that finding an organism with a dissimilar glycolysis metabolic pathway or genetic code would not falsify the hypothesis of universal common ancestry.  The discovery could be accommodated by the theory in several ways, as I have explained.  So Hunter is indeed correct when he says:

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.  For if the code is arbitrary, why should there be just one? The blind process of evolution would explain why there are multiple codes.  In fact, in 1979 certain minor variations in the code were found, and evolutionists believe, not surprisingly, that the variations were caused by the continuing evolution of the universal genetic code.  Of course, it would not be a problem for such an explanation to be extended if it were the case that there were multiple codes.  .  .  .  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, 38.)

Dr. Theobald admits that biochemical similarity fits easily within the creation framework, but he considers that meaningless because the creation framework can accommodate any data.  Yet, the same can be said of the hypothesis of universal common ancestry.  One committed to that theory (“the fact of evolution”) can interpret the data consistently with the theory.  As Hunter says: “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.” That is what Dr. Theobald is doing. 

Dr. Theobald asserts that ReMine’s biotic message theory is compatible with universal common ancestry, despite recognizing that ReMine disagrees with him.  It is a bold man indeed who claims to understand ReMine’s theory better than ReMine.  In claiming that ReMine’s theory is compatible with common descent because a single designer could “have used evolution to make all of life look like a unified work,” Dr. Theobald reveals a misunderstanding of ReMine’s work.  The unity of life is only part of message theory.  The theory asserts that life was designed simultaneously for survival, to look like the product of a single designer, and to resist all macroevolutionary explanations. 

In illustrating how biochemical similarities might be part of a Creator’s design, I quoted Duane Gish for the point that the similarities might have been to permit humans to eat plants and animals.  Dr. Theobald rightly remarks that I (through Gish) overstated the matter in suggesting that this was a necessary rather than merely a conceivable divine rationale.  The point, however, is that biochemical similarities are compatible with a creation viewpoint, something Dr. Theobald concedes. 

Dr. Theobald ends this section by accusing me of constructing another straw man when I wrote: “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.” He says he was not claiming that living things have the functions of living things, which he agrees would be a tautology, but that living things have similar structures and mechanisms that perform the functions of living things. 

The fact is that he made both claims.  He stated under the prediction: “If every living species descended from an original species that had these four obligate functions, then all living species today should necessarily have these functions” (emphasis supplied).  For exposing that tautology, I am accused of chicanery. 

Prediction 2:  A Nested Hierarchy of Species

Dr. Theobald claims that the nested hierarchy of existing species^[2] fulfills a falsifiable prediction of the hypothesis of universal common ancestry and therefore constitutes evidence that the hypothesis is true.  I argued that, because descent from a common ancestor does not necessarily result in a pattern of nested hierarchy, the hypothesis of common ancestry would not be falsified if organisms did not fit that pattern.  That is, a nonhierarchical pattern could be explained consistently with common ancestry by appeal to processes that work against a nested hierarchy.  Dr. Theobald accuses me of error in claiming it is possible for descent from a common ancestor to result in a non-nested pattern.  He is wrong. 

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.^[3]

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 he claims to prove universal common ancestry regardless of “whether Darwinism, Lamarckism, or something else is the true mechanism of evolutionary change,” he cannot offer evidence that depends for its probative value on the exclusion of any of these mechanisms.  In other words, 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, Lamarkism, or something else is the true mechanism of evolutionary change,” which is the proposition being argued by Dr. Theobald.^[4]

I suggested that the hierarchical pattern of life is compatible with divine creation of separate kinds by pointing out (through Hunter’s quote) that Linnaeus, the father of biological classification, saw them as compatible.  In response, Dr. Theobald attempts a reductio ad absurdum, claiming that this reasoning would cast doubt on Newton’s theory of gravity.  He writes:

According to [this] twisted 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.  People before Newton, such as Aristotle, thought that apples were attracted to the earth because they were primarily made of the “earth” element.  Obviously this pattern (falling) does not force one to embrace the inverse square law.  The fact that people were wrong about physical explanations in the past is not an argument against modern scientific theories. 

In his rush to criticize, Dr. Theobald misses the mark completely.  I do not use Linnaeus’s belief in separate divine creation (multiple ancestors) as evidence that universal common ancestry is false.  Rather, I use his simultaneous belief in nested hierarchy and separate divine creation as evidence that those two are logically compatible.  In terms of Dr. Theobald’s analogy, I am citing the fact Aristotle believed in both falling and elemental attraction as evidence that those beliefs are compatible, not as evidence that Newton’s theory is false.  (His analogy is confused a bit more by the fact the inverse square law is really a description or quantification rather than an explanation.) Since Dr. Theobald recognizes that the phenomenon of falling is compatible with multiple explanations, he should have no objection to the point. 

Dr. Theobald accuses Hunter (through my quoting of him) of misrepresenting evolutionary theory in claiming that the principle of divergence is distinct from common descent.  According to Dr. Theobald, Darwin’s principle of divergence is simply another name for (“is otherwise known as”) common descent.  That is incorrect.  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, www.lib.cam.ac.uk/Departments/Darwin/intros/vol6.html).  For my part, I misunderstood that Darwin’s principle of divergence related to a specific pattern of nested hierarchy, not to nested hierarchy in general. 

Dr. Theobald suggests that I am confused about whether common descent must include branching because I stated, “Even a mechanism of descent that includes branching events does not ensure a nested pattern.” He asks, “If multiple species evolved from a common ancestor, how could they have arisen without branching?” Of course the coexistence of multiple species requires branching.  I simply was acknowledging that there is a mechanism of descent (anagenesis) that does not include branching, while making the point that cladogenesis would not guarantee a nested pattern (for the reasons given above). 

After quoting from my critique ReMine’s assertion that nested hierarchy is not an inevitable consequence of common ancestry (because of various processes that can work against that pattern), Dr. Theobald writes:

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 theory.  .  .  .  ReMine simply does not understand how the scientific method works. 

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).  Rather, he 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. 

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 in science. 

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 an explanation. 

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. 

Dr. Theobald next charges me with wrongful imputation of a theological assumption.  He writes: “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.”

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. 

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. 

Think of it this way.  If both scorching and painting could make a cloth brown, one could not logically infer that a cloth had been scorched solely from the fact it was brown.  If one asserted that the cloth’s brown color was evidence of scorching, one would be assuming implicitly that the cloth could not have been painted.  Otherwise, the assertion would be incoherent. 

Dr. Theobald accuses me of being confused and not understanding the difference between artificial and genuine nested hierarchies because I wrote: “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.” The irony is that he is accusing me of not appreciating the very point I was making. 

The reason I said his statement that objects like buildings, furniture, and cars cannot be classified in a nested hierarchy required elaboration was that, taken at face value, the statement appears to exclude the possibility that such specially designed objects could be classified artificially in a nested hierarchy.  Thus 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”). 

The confusion continues as Dr. Theobald asserts that the basis for distinguishing artificial and genuine hierarchies became more rigorous six years after Ridley’s book was published.  For that reason, he says that my quoting Ridley is on a par with quoting Lord Kelvin to argue against the existence of x-rays.  But since 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, the analogy is inapposite. 

Predicition 3: Convergence of Independent Phylogenies

It is claimed here that phylogenies constructed from comparisons of certain biological molecules are evidence for the truth of universal common ancestry because they fulfill the falsifiable prediction of the hypothesis of common ancestry that molecular phylogenies will “converge” on the standard morphological phylogeny (Figure 1).  As I showed in the critique, it is not a falsifiable prediction of universal common ancestry that molecular phylogenies will “converge” on the standard phylogenetic tree. 

I provided abundant evidence of incongruities between morphological and molecular phylogenies.  Indeed, paleontologist Michael Benton wrote in 1998:

Many hundreds of phylogenies of mammals have been published, some based on morphological data and others based on molecular data (proteins, nucleic acids), and yet there is no evidence that these hypotheses of relationship are converging on a single viewpoint.  Indeed, for some problems, such as the relationships of the orders of placentals, the reverse seems to be the case: with more work, and the introduction of new data, the variety of postulated phylogenies increases.  (Michael J.  Benton, “Molecular and morphological phylogenies of mammals: Congruence with Stratigraphic Data,” Molecular Phylogenetics and Evolution 9 [no.  3, June]: 398.)

These incongruities are not an artifact of coarse measurement; they are data.  Yet, none of them is deemed to have violated the “prediction” (and thus to have falsified the hypothesis) because various processes can be invoked to explain them away.  Recall the comment of biochemists Schwabe and Warr:

We believe that it is possible to draw up a list of basic rules that underlie existing molecular evolutionary models:

1. 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.
2. Complexity evolves mainly through duplications and mutations in structural and control genes.
3. 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.
4. 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.)

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. 

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. 

Dr. Theobald next claims that I contradicted myself in my “eagerness to ‘disprove’ common descent.” In the first place, I was not attempting to disprove common descent.  Rather, I was critiquing Dr. Theobald’s claim to have proved common descent.  He assumed the burden of proof in his article and cannot slough it onto me. 

Secondly, 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.  Dr. Theobald apparently believes that no phylogenies could be considered “discordant” if all phylogenies could be accommodated, but that is simply not true.  Inconsistent phylogenies can be considered discordant where certain assumptions about evolutionary mechanisms have been added to the hypothesis of universal common ancestry (i.e., where certain constraints on the processes that work against congruity are assumed).  Since the bare hypothesis of universal common ancestry imposes no constraints on processes that work against phylogenetic congruity, when inconsistent phylogenies conflict with assumed constraints, the hypothesis can be preserved simply by changing the assumptions.  That is precisely what is done, as Schwabe and Warr explain. 

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).  Apparently Dr. Theobald does not understand the difference between data and the assumptions under which data are interpreted.  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?

Dr. Theobald’s challenge to construct a molecular phylogeny to his specification (that places chimps closest to fish, humans closest to birds, cows closest to insects, and bacteria closest to marsupials) misses the point.  The point is that his specified molecular phylogeny would be compatible with the bare hypothesis of universal common ancestry.  That hypothesis says nothing about when and where certain processes that affect the divergence of biological molecules will operate.  Thus, it leaves one free to assume that those processes operate whenever and wherever is necessary to produce the specified phylogeny.  Dr. Theobald again is confusing what the data are with what the hypothesis demands that they be, which is a crucial error for one claiming as evidence the fulfillment of a falsifiable prediction. 

In addition to the fact the hypothesis of universal common ancestry does not predict that molecular phylogenies will match the standard morphological phylogeny, I pointed out that, even if the standard phylogeny was matched by multiple molecular phylogenies, it would not prove that the groups in question descended from a common ancestor.  (As I noted, to have relevance to Dr. Theobald’s claim of universal common ancestry, the analysis would need to include all groups of living things.) The molecular differences could be linked to the morphological differences for some reason other than descent.

I cited Hunter’s example of automobiles to illustrate how phylogenies constructed from comparisons of different traits could be congruent without the subjects of the comparisons having descended from a common ancestor.  Though evolutionists have used automobiles and similar things as examples of nested hierarchy, Dr. Theobald objects because he does not believe automobiles constitute a genuine nested hierarchy, which means that a comparison of their various traits would not produce congruent phylogenies.  Be that as it may, the point I was attempting to illustrate cannot be denied.  Common descent is not essential for nested hierarchy and therefore is not a necessary inference from the congruence of phylogenies based on different traits. 

Dr. Theobald next accuses me (again) of having insufficient knowledge of basic molecular biology and genetics because I stated “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.” More specifically, he rejects the suggestion (quoted from biochemist Gish and biologist Brand) that differences in biochemistry may, for functional reasons, correlate with differences in physiology, which may, in turn, correlate with differences in morphology.  In his opinion, molecular biology and genetics have eliminated the possibility of there being a functional reason for biological molecules to correlate with physiology, and thus the correlation that exists between biochemistry and morphology must be the result of common descent. 

As proof that molecular biology and genetics have eliminated the possibility of there being a functional reason for biological molecules to correlate with physiology, Dr. Theobald offers the fact that cytochrome c (and other ubiquitous proteins) from a variety of species works “just fine” in yeast that lack a native cytochrome c gene.  But even if “just fine” means “as well as the native variety,”^[5] this evidence is not dispositive of the issue.  The fact human cytochrome c (or some other human protein) works “just fine” in yeast does not prove that it is not better suited for humans than for yeast.  For that, one would need to show that yeast cytochrome c works in humans as well as human cytochrome c and that it does so throughout all phases of life from conception on. 

If that could be established, it would still leave open the possibility that human cytochrome c had been designed originally to perform functions in humans beyond the bare “common function.” If those additional functions were somehow lost, perhaps in the Fall, leaving only the common function, the current correlation of cytochrome c with morphology would be a remnant of its original design.  Granted this is speculation, but it is relevant because the issue is whether the cytochrome c evidence cited by Dr. Theobald eliminates the possibility of a functional basis for the correlation between cytochrome c and morphology.  It does not. 

And, as I pointed out elsewhere, even if the current correlation of cytochrome c and morphology was unrelated to any differences in how the protein functions, there still could be reasons for the pattern other than common descent.  If, for example, ReMine is correct that nested hierarchy is a crucial aspect of the Creator’s biotic message, then one would expect that nesting to be expressed at the biochemical as well as the morphological level. 

So my disagreement with Dr. Theobald on this point is not because I am ignorant of the basis of his claim.  After all, he relied on the same evidence in the original article.  I just think he is claiming more for that evidence than is warranted. 

Dr. Theobald accuses me of inserting a red herring into the discussion because I mentioned two puzzles the cytochrome c data present from a Neo-Darwinian perspective.  The first is that 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. 

I expressed the puzzle presented by these data in this way:

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 1998, 291.)

According to Dr. Theobald, this is a red herring because “[c]ommon 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.” I agree that the bare hypothesis of common descent says nothing about the process by which proteins diversify, but Dr. Theobald, in contradiction of his stated purpose, went beyond that hypothesis in appealing to the differences in proteins as evidence of common descent.  In doing so, he necessarily made some assumptions about the process by which proteins diversify (otherwise, no inference could be drawn from a pattern of diversity).  So facts about protein diversification that are puzzling in terms of standard evolutionary thinking are indeed relevant. 

Dr. Theobald asserts