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29+ Evidences for MacroevolutionA Response to Ashby Camp's "Critique"Copyright © 1999-2003 by Douglas Theobald, Ph.D.Anti-evolutionist 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 article. 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 characterized by:
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. OutlinePrediction 1: The fundamental unity of lifeA straw manAshby Camp writes:
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 1:
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:
"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 by gradualism). Conflation of mechanism with gradualismCamp writes:
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 introduction:
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:
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:
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 29. 6 A Misunderstanding of Evolutionary FundamentalsCamp continues with ReMine's words:
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:
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:
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. The Logical Fallacy of EquivocationCamp continues with Hunter's quote:
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 writes:
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 universals. An Unscientific "Alternative": The Fallacy of Untestability
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 BiochemistryCamp 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:
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 manCamp ends his criticism of Prediction 1 with this straw man:
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 speciesMisrepresentation of Evolutionary Theory and Erroneous LogicCamp'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:
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 TheoryCamp has since replied to this criticism:
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 ScienceCamp then tries to support this misunderstanding with another quote from Hunter:
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 ScienceHunter's quote continues:
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.
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:
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.
More Misrepresentation of Evolutionary Theory and Misunderstanding of the Scientific Method:Walter ReMine's Views of the Nested HierarchyCamp appears to be confused about whether common descent must include branching of species or not:
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:
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 theory. 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:
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 theory.
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:
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:
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 hierarchies. Since this was written, Camp has replied:
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 29. 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 highly unlikely. Michael Denton's Views of the Nested HierarchyCamp then goes on to quote another confused anti-evolutionist, Michael Denton, in support of his assertion that common descent does not predict a nested hierarchy:
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:
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 evolution. 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 writes:
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:
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."
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:
This was written by the same man who scribed:
One wonders how Camp can feel justified in quoting Denton's past confusions about common descent. Camp has responded to this:
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 ProjectionAt this point, Camp leaves science and enters into theological arguments:
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 function" (Brand 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 own admission. Camp has written in defense of his unsubstantiated theological accusations:
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 " model 5." 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 MethodCamp continues in defense of his accusations:
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:
Camp quoted Brand in support:
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 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 testability. Camp continues with his original critique:
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 TheoryCamp concludes his criticism of this point with an attack on the very notion of cladistic classification:
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:
And common descent explains it. A Classic Out-of-Context QuoteCamp concludes this misunderstanding with a quote from a well-known evolutionary biologist, which only appears to support his point:
Camp carefully and quite misleadingly omits the very next sentence:
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:
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:
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 phylogeniesMore Misrepresentation of Evolutionary TheoryCommon 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:
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 conclusion:
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 trees. 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 discipline. Camp has offered a defense of his erroneous views:
"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). A Self-contradiction -- the Fallacy of InconsistencyUnfortunately, 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:
and follows with this a few paragraphs later:
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 here:
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 Evolutionary Methods
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
\/ \/ \ / \/
\ / \/ /
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\ / /
\ / /
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V
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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:
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. Two Wrongs make a RightCamp, however, has attempted to justify his accusations:
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").
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.
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.
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 ancestry." 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. Another logical fallacy: the argument from authorityIn 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):
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 known in 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 claims? No. 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 1984). Second, increases in complexity due to gene duplications and mutations have been observed in the wild and the lab (Copley 2000; Futuyma 1998, p. 274; Lederberg and Lederberg 1952; Lee et al. 1998; Ohno 1984; Okada 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; Okada 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 factual. 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 evolution) (Holliday 1964; Meselson and Radding 1975; Szostak et al. 1983; Nagylaki 1983; Hilliker 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 is factual. 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:
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 practice. 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 3. 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 imperfect. 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 GeneticsCamp even doubts that correspondence between molecular and morphological phylogenies would be evidence for common descent:
Though Camp's point is valid, it already has been addressed extensively in Prediction 3, 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 TheoryCamp goes on to quote Hunter concerning this point:
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. A False AnalogyCamp continues with Hunter's quote:
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 man. 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. Insufficient Knowledge of Basic Molecular Biology and GeneticsCamp 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:
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:
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 elements. Another Red Herring: Insufficient Knowledge of "Neo-Darwinism"Camp finds yet another "problem" with the cytochrome c data and its implications for common descent:
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:
And, as we have shown earlier, Michael Denton knows very little basic evolutionary theory1. 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":
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. Disregard for Basic Mathematics: Probability, Statistics and the Fallacy of AccidentCamp evidently does not understand the probabilistic nature of genetics, since he is surprised at a small minority of "anomalous" cytochrome c sequences:
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 statistical fallacy. 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 and carp 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:
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 Evidences":
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 distance-based algorithms. Apparently, Camp not only misunderstands basic genetics but also has a deep misunderstanding of basic mathematics (probability and statistics), as he later chides in response:
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. 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 1994; 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 ancestorsMore Misrepresentation of Evolutionary Theory: Erroneous Logic
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:
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 descent. Misunderstanding of the Scientific MethodCamp has replied:
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 G. Mr. Camp misrepresented evolutionary theory because he said:
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:
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:
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.
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
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:
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 ControversyIronically, the inflexibility of this aspect of the standard phylogenetic tree is well-evidenced by Camp's next statements:
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 (Benton 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:
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:
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 1985; Benton 1991; Gauthier et al. 1988; Hopson 1991; Kemp 1988; Witmer 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 correct. Camp has responded:
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:
Precisely. Let's pause here to let the irony of Camp's words soak in:
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 results (Benton 1985; Benton 1991; Gauthier et al. 1988; Hopson 1991; Kemp 1988; Witmer 1991). 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:
This is false. Recall Camp's original claim:
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
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 statements:
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
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:
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 1868; Huxley 1870a), as had many other prominent paleontologists in the early 20th century (Witmer 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 Ticinosuchus (Barsbold 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; Feduccia 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:
More Misunderstanding of the Scientific Method, and Another Self-contradictionBack to Camp's criticism of the prediction of intermediate/transitional organisms:
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:
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. Faulty Logic
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. Prediction 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.
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:
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
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 original prediction 4 and prediction 25:
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:
In other words, Camp understands that common descent, at least in its modern incarnation, does not predict that transitional forms are necessarily common ancestors2. 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:
Referring to his famous figure, Darwin explained:
And,
More relevant evidence is given from the early evolutionary biologist, Thomas Henry Huxley:
From a popular introductory evolutionary college textbook from the '50s and '60s:
From a modern introductory evolutionary textbook:
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 ScienceMr. Camp concludes this section with a veiled attack upon the scientific method itself:
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:
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:
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 physics. 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 ancestorsMore Misrepresentation of Evolutionary Theory, and Another Self-contradictionCamp correctly restates the prediction and then begins his criticism in earnest:
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:
Yes, and that is exactly why a phylogeny predicts the relative order in which taxa have arisen during evolution. Camp has responded to this:
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 ancestry:
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.
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
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 in Prediction 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."
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.
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:
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.
In fact, that "impression" is quite correct, and it is based on numerous published analyses from many different researchers.
These statements are ludicrous. Wise's analysis has never been published; how does Camp know what Wise did?
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:
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 descent. ConclusionCamp'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 words):
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:
What is this "something entirely different"? From the second sentence of Camp's critique:
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.
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
scientific evidence?
Footnotes1. 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 (see Ohta 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 1984) Back 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:
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 pertinent here:
Wise has expounded:
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:
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. 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![[Denton's Figure]](../img/macroevolution/denton.gif)
![[Figure C1]](../img/macroevolution/evo_dist.gif)
