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(Evolution vs. Creationist Pseudoscience: No Contest--continued, Part B)

SECTION 2: The supposed inability of microevolution (even in principle) to explain macroevolutionary "leaps."

For the most powerful demonstration that microevolution can or could give rise to the macroevolutionary changes seen in the fossil record, one actually does not need to go much further than the known record of transitional forms, such as are documented in Kathleen Hunt's detailed literature review covered just previously. There are numerous examples of gradual transition sequences that, by the time the end of the sequence is reached, demonstrate significant anatomical changes in form from the beginning to the end of the sequence, in stepwise fashion.

The most dramatic and well-documented example demonstrating macroevolutionary changes through gradual transition is the transitional sequence from reptiles to mammals. In her "Transitional Vertebrate Fossils FAQ, Part 1B", Hunt says:

This is the best-documented transition between vertebrate classes. So far this series is known only as a series of genera or families; the transitions from species to species are not known. But the family sequence is quite complete. Each group is clearly related to both the group that came before, and the group that came after, and yet the sequence is so long that the fossils at the end are astoundingly different from those at the beginning. As Rowe recently said about this transition (in Szalay et al., 1993), "When sampling artifact is removed and all available character data analyzed [with computer phylogeny programs that do not assume anything about evolution], a highly corroborated, stable phylogeny remains, which is largely consistent with the temporal distributions of taxa recorded in the fossil record." Similarly, Gingerich has stated (1977), "While living mammals are well separated from other groups of animals today, the fossil record clearly shows their origin from a reptilian stock and permits one to trace the origin and radiation of mammals in considerable detail." For more details, see Kermack's superb and readable little book (1984), Kemp's more detailed but older book (1982), and read Szalay et al.'s recent collection of review articles (1993, vol. 1).

In Darwin on Trial on pp. 77-79, Johnson manages to dismiss the entire reptile-to-mammal transitional sequence with his usual casuistry and ignorance of the evidence--claiming that because the exact species-to-species transitions are not yet known, and that BECAUSE (!) there are so many possible lines of ancestry, evolutionists have been forced into the position of postulating that mammals could only have evolved via a mish-mash of multiple lines of ancestry rather than through a direct sequence as evolutionary theory would require. As the above indicates, Johnson just simply doesn't know his evidence because he doesn't care to look too closely, and he is so facile with his arguments, he even fakes himself out.

Within the mammalian line, especially the closer one gets to the present where more fossils are able to be recovered, one can begin to see more fine-grained sequences, including the finest-grained possible: direct species-to-species transitions. To cite just a few examples from the fossil record of early primates given by Hunt (this one at the link, "Transitional Vertebrate Fossils FAQ, Part 2A":

Early lemur-like primates: Gingerich (summarized in 1977) traced two distinct species of lemur-like primates, Pelycodus frugivorus and P. jarrovii, back in time, and found that they converged on the earlier Pelycodus abditus "in size, mesostyle development, and every other character available for study, and there can be little doubt that each was derived from that species." Further work (Gingerich, 1980) in the same rich Wyoming fossil sites found species-to-species transitions for every step in the following lineage: Pelycodus ralstoni (54 Ma) to P. mckennai to P. trigonodus to P. abditus, which then forked into three branches. One became a new genus, Copelemur feretutus, and further changed into C. consortutus. The second branch became P. frugivorus. The third led to P. jarrovi, which changed into another new genus, Notharctus robinsoni, which itself split into at least two branches, N. tenebrosus, and N. pugnax (which then changed to N. robustior, 48 Ma), and possibly a third, Smilodectes mcgrewi (which then changed to S. gracilis). Note that this sequence covers at least three and possibly four genera, with a timespan of 6 million years.

...And here are some transitions found by other researchers: Rose & Bown (1984) analyzed over 600 specimens of primates collected from a 700-meter-thick sequence representing approximately 4 million years of the Eocene. They found smooth transitions between Teilhardina americana and Tetonoides tenuiculus, and also beween Tetonius homunculus and Pseudotetonius ambiguus. "In both lines transitions occurred not only continuously (rather than by abrupt appearance of new morphologies followed by stasis), but also in mosaic fashion, with greater variation in certain characters preceding a shift to another character state." The T. homunculus - P. ambiguus transition shows a dramatic change in dentition (loss of P2, dramatic shrinkage of P3 with loss of roots, shrinkage of C and I2, much enlarged I1) that occurs gradually and smoothly during the 4 million years. The authors conclude "...our data suggest that phyletic gradualism is not only more common than some would admit but also capable of producing significant adaptive modifications."

Though there are in fact numerous examples of known transitional fossils which add up to macroevolutionary change, as detailed in Kathleen Hunt's literature review cited above--which puts the lie to creationist claims there aren't any at all--it is nevertheless true there are also many gaps in the fossil record. When expectations that the fossil record was not going to support the idea it should be completely full of gradualist transitional sequences, evolutionary biologists realized the existence of gaps or rapid transitions was as real as the existence of gradual transitional forms, and had to be explained too. This led to the development of the theory of Punctuated Equilibrium, discussed further below.

Now of course, Phillip Johnson contends that in having proposed (a) punctuated equilibrium, and/or (b) that microevolutionary changes can add up to macroevolution even in relatively short geological timespans, evolutionists are welshing and "changing their story." But that is exactly what good science is: recognizing when a theory is not complete enough or accurate enough to explain the evidence adequately, scrapping what doesn't work, and reformulating it so it does face the additional facts and attempt to adequately explain them. First Johnson faults scientists for not facing the evidence; then when they do exactly what he is asking and reformulate evolutionary theory to better account for it, he complains that they have "changed their story"! What does this lawyer want? He can't have it both ways. It has been two-and-a-half decades now--since 1971 or 1972 when Eldrege and Gould initially proposed the theory of "punctuated equilibrium"--that the fact of "gaps," or "sudden" or "rapid" transitions has been squarely acknowledged.

In addition to general punctuated equilibrium theory, however, there have now been two or three recent developments depicting how macroevolution can in fact--and/or in theory--take place as the cumulative result of microevolutionary changes. (One common misunderstanding about P.E. is to assume that it is intended as a complete replacement for gradualistic scenarios, which is not the case--it's merely a modification extending and refining the explanatory power of earlier neo-Darwinism. P.E. theory in fact does not depend on "jumps," as it says nothing about the mechanisms about which rapid speciation might occur. What it does say is that speciation is most likely to occur in a certain way [rapidly among small populations in fringe geographic areas], but that speciation is still gradualistic even if rapid.) These recent developments are:

As we've seen above, there is very strong fossil and genetic evidence that micromutation can indeed lead to macromutations. A related question is the claim by Fruitarian XYZ in their Raw-Food posting that the creation of species can't be directly observed any more than can supernatural creation by God; and that while natural selection can winnow out species presumably created by some other mechanism, it cannot, even in combination with micromutations, be responsible for the creation of new species by itself. In refutation of this, we offer the following:

Speciations That Have Been Directly Observed or Can Be Directly Inferred from Recent Circumstantial Evidence

The next two examples are available (along with the scientific references) in the "Some More Observed Instances of Speciation" FAQ.

For a more complete listing of observed speciations in the natural world plus other observed experimentally in the lab, including the scientific references, see the two following links:

SECTION 3: Since embryological development of organisms before birth does not retrace their species' historical evolutionary development like early Darwinists said, evolution is supposedly thereby invalidated.

The Embryology Argument: A "Straw Man"

Where the argument from embryology is concerned, which Johnson cites in Darwin on Trial as evidence against evolution, there is not much that can be said except it is puzzling why Johnson even included it in the book at all (or Fruitarian XYZ in their Raw-Food posting) because it has been decades since anybody seriously thought that embryological development of organisms prior to birth ought to exactly recapitulate their species' evolution as seen in the fossil record.

All evolutionists say is that later evolutionary forms have inherited--as they have in other of their features--an embryological developmental pattern from earlier ancestors which has been modified. They also point out that embryology can demonstrate how vestigial structures may be retained from earlier stages of evolution and reformed or put to different uses as the animal develops. And while it is certainly true that scientists may sometimes use time-lapse photography of embryological development as a compelling visual aid to give some feel for the relatedness of different species' forms and how one could have "morphed" or developed into another, to suggest evolutionists still believe the old "embryology" chestnut that "ontogogeny [exactly] recapitulates phylogeny" is one of the oldest straw men in the books.

Johnson strays far off-target in attempting to make big hay of the fact that the PBS show Nova displayed such embryological sequences in introductory links on the website that contains his online debate with biologist Kenneth Miller. His misplaced emphasis also seems based on the misunderstanding of assuming that the embryological developmental sequence of animals can only be changed by mutations that are tacked onto the end of the previously existing embryological sequence, which if it were the only route for changes, could indeed plausibly cause it to mirror the species' past evolutionary as it unfolded in the past. But as we now know, that is not how it happens. In fact, mutations can, do, and have introduced changes into the embryological developmental sequence of species at any given point in the sequence--not just the end of it--making the embryological development of any given animal suggestive of its early evolution at times, but at other times not.

So while early evolutionists initially thought that the development of embryos ought to mimic the evolutionary tree of progression for the species the embryo belongs to, it has been long, long time now that this theory has been scrapped. (Miller has a very brief summary at the above link.) It is creationists who stick themselves with this old idea, not evolutionists.

SECTION 4: Creationists say that molecular genetics does not give us the ability to impute common ancestors any more than do other physical features--it's just another way of classifying organisms based on their form, in this case their genetic "form."

Recent molecular genetics techniques now enable biologists to determine the amount of "genetic distance" between currently living species. (It is also just now beginning to allow us to actually look at surviving DNA from ancient fossilized creatures if any remaining viable DNA is present, though this has been very rare so far.) This information can then be used to reconstruct family trees of past genealogical evolutionary relationships from a completely independent source other than the fossil evidence. As it has turned out, the picture from the molecular evidence agrees with the fossil record very closely with only very minor differences.

Since genetic molecular sequences are the actual physical pieces of organisms (with occasional mutations, which give rise to the "genetic distance" between organisms) that are handed down from one generation to this next--a process which can be directly observed in the laboratory--molecular evidence provides the strongest evidence possible that the genealogical relationships imputed by the fossil record actually occurred, short of being able to go back in a time machine and actually observe them.

That the pattern of past genealogical relationships suggested by the molecular genetic evidence agrees so closely with what the fossil record says, with only very minor differences, is considered by scientists to be spectacular confirmation of the evolutionary genealogical relationships as judged by the fossil record. In other words, here is an overwhelming example of confirmation of earlier predictions by a completely separate line of evidence--one of the prime criteria for what constitutes "science."

In Darwin on Trial, however, Phillip Johnson dismisses modern molecular genetic evidence's ability to determine geneaological relationships on the grounds that he thinks these molecular genetic similarities between organisms are no different in principle than the comparative differences we also see in an organism's adult physical form (such as what we see as the fossil evidence.) This bald assertion of course ignores the fact that while the characteristics of form preserved in the fossil record are not directly handed down, adult form does develop from the molecular genetic sequences that are directly handed down from parent organism to child--which is a process known to occur based on firsthand observation in the laboratory.

To therefore assume that the process of inheritance is not how the genetic similarities and differences observed between different organisms came about in the first place is one of the most perverse twists of logic possible. Only by arbitrarily postulating an untestable assertion that a supernatural being, using genetic sequences as nothing more than an "artist's palette of painting material," so to speak, in whimsically creating the range of species we see in the fossil record as we see today, is Johnson able to philosophically justify dismissing the overwhelming confirmation of the fossil record by molecular biological evidence.

The extreme whim and arbitrariness of creationists in lodging objections to points like this can be seen in the fact they don't object to many other similar areas of biology where exact causation may be just as unknown as the macroevolutionary changes that cause creationists to go so bug-eyed. For instance, as biologist Kenneth Miller points out in his online debate with Johnson, no one yet knows what force causes chromosomes to move apart when cells divide, yet creationists do not jump all over the unknown details here, and infer that only the intervening hand of some supernatural force or being must be responsible. Likewise, how and why an embryo can seemingly miraculously differentiate from a small clump of cells after fertilization into an immensely complex organism prior to birth is not something for which they seem to feel it is necessary to resort to the supernatural for explanations either.

Creationists do not say it is "materialist philosophy" in these cases to assume biological mechanisms underlie events even if research has not yet proceeded to the point it can actually point them out with super-reductionist precision. Why then do they have such trouble with "unseen" genealogical relationships in the fossil record? Just because we cannot "go back" in the past and see things with our own eyes as they unfolded at the time does not mean we cannot "go back" with other techniques that reveal the factual history.

There is also a second way in which the modern genetic evidence even more powerfully demonstrates evolutionary genealogical relationship than by measures of genetic distance alone. This route examines the phenomenon sometimes called "plagiaristic copying" of genetic errors that occasionally occur when genes are duplicated. The way this is usually explained is by way of analogy to how plagiariam of manuscripts is often detected:

If a plagiarist in copying a manuscript also copies telltale signs or errors in the manuscript--that the plagiarist is not aware are actual errors--exactly as they occurred in the manuscript (i.e., unrecognized typographical errors, or errors of fact, such as incorrect addresses or phone numbers which when copied have been known to trip up plagiarizers putting out directories without researching the information for themselves) then the existence of these errors in the plagiarized copy is considered by the courts as sufficiently powerful to establish the fact of plagiarization beyond any doubt. The reasoning is that nobody would purposely copy errors if they actually knew they were errors--and the fact the same exact errors exist in the plagiarized copy indicates they had to have been reproduced by copying the original.

The way the analogy works with respect to genetic copying errors is as follows. Normally, when mutations occur in genes, they are either quickly eliminated (if they have a detrimental impact on survival and reproduction), so that no errors are retained. Or else the mutations are beneficial, in which case they contribute to survival and are retained because they are beneficial. However, there is a separate class of copying errors that can occur in what are called "pseudogenes" (extra copies of genes within portions of an organism's genome that are themselves nonfunctional), so that the errors in the pseudogenes continue to be reproduced from parent to child even though they have no survival effect on the organism.

What these errors amount to, then, is "plagiaristic errors" that persist from one generation to the next. Thus, when exact copies of these pseudogenes are found in differing organisms--and in identical locations in the gene sequences of each organism--it is considered nigh onto airtight evidence that the two organisms had a common ancestor that had that same pseudogene. And there have now been many examples found of these so-called "plagiarized" genetic copying errors in pseudogenes, that when analyzed, have confirmed the same pattern of genealogical relationships suggested by both the fossil evidence and "genetic distance" studies.

For a list of the examples and a far more in-depth discussion of pseudogenes and exactly why and how telltale plagiaristic copying errors demonstrate genealogical relationship, see "Plagiarized Errors and Molecular Genetics," by Edward Max, M.D., Ph.D., a molecular geneticist doing current research on pseudogenes.

Again, the only way to argue around what the copying of plagiaristic errors in pseudogenes indicates is to argue that God in his/her/its infinite wisdom inadvertently let errors creep into the genetic apparatus of human beings and all other creatures. That hardly paints a picture of an intelligent God. Or perhaps God decided to stick them in just to fool us in our scientific research. But what kind of God would do that? It paints God as a malicious being just having misanthropic fun that no one in their right mind would want to put their trust in. You either have a God who is an inept klutz at designing things or a God who is malicious. Or if God is in direct control, then he/she's fallen asleep at the wheel.

To make this point clearer and perhaps closer to home for creationists:

Terry Gray, a former elder in the Presbyterian church, points out in his review of Darwin on Trial that creationists themselves use this same type of inferential logic all the time to reveal the threads of genealogy in biblical lines of authorship when they are trying to determine the source of ancient manuscripts. Says Gray:

Take for example New Testament manuscripts. When we find extant manuscripts that have inserted sentences or paragraphs (e.g., the concluding sentence in the Lord's Prayer) and compare them with other extant manuscripts that are otherwise identical, we do not conclude that these two manuscripts are completely independent in origin. We re-create the scenario that at some point in the manuscript history, a scribe either added or deleted the inserted text. All manuscripts deriving from that errant copy would also contain the error.

The point of the analogy here is that the similarity between imputing a line of ancient authorship by using the presence or absence of inserted text by scribes that gets handed down to further copied manuscripts is exactly the same logic used to infer common genealogical ancestry between organisms and species by noting the mutations and certain identifying gene sequences they hold in common. That creationists are so conveniently willing to dismiss the same logic when used by evolutionists shows just how arbitrary their program of denial really is. They aren't really objecting on scientific grounds, they are objecting on religious grounds. Which is fine if they want to cop to the fact their objections are from religious grounds. But to then claim their grounds are scientific is plainly dishonest--wanting to have the veneer of scientific respectability without the price of consistently abiding by the logic required to be scientific.

SECTION 5: Evolution is supposedly not fact, only a theory.

Perhaps the best summaries of the above point come from the scientists themselves (Gould, Ernst Mayr, Dobzhansky, Futuyma, etc.). To quote from the Talk.Origins site (these three following quotes come from the passages in the "Evolution is a Fact and a Theory" FAQ, put together by Laurence Moran--

From Stephen Jay Gould:

In the American vernacular, "theory" often means "imperfect fact"--part of a hierarchy of confidence running downhill from fact to theory to hypothesis to guess. Thus the power of the creationist argument: evolution is "only" a theory and intense debate now rages about many aspects of the theory. If evolution is worse than a fact, and scientists can't even make up their minds about the theory, then what confidence can we have in it?...

Well evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts don't go away when scientists debate rival theories to explain them. Einstein's theory of gravitation replaced Newton's in this century, but apples didn't suspend themselves in midair, pending the outcome. And humans evolved from ape-like ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered. Moreover, "fact" doesn't mean "absolute certainty"; there ain't no such animal in an exciting and complex world. The final proofs of logic and mathematics flow deductively from stated premises and achieve certainty only because they are NOT about the empirical world. Evolutionists make no claim for perpetual truth, though creationists often do (and then attack us falsely for a style of argument that they themselves favor). In science "fact" can only mean "confirmed to such a degree that it would be perverse to withhold provisional consent." I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms. Evolutionists have been very clear about this distinction of fact and theory from the very beginning, if only because we have always acknowledged how far we are from completely understanding the mechanisms (theory) by which evolution (fact) occurred...

--Stephen J. Gould, "Evolution as Fact and Theory"; Discover, May 1981

And this from Theodosius Dobzhansky:

Let me try to make crystal clear what is established beyond reasonable doubt, and what needs further study, about evolution. Evolution as a process that has always gone on in the history of the earth can be doubted only by those who are ignorant of the evidence or are resistant to evidence, owing to emotional blocks or to plain bigotry. By contrast, the mechanisms that bring evolution about certainly need study and clarification. There are no alternatives to evolution as history that can withstand critical examination. Yet we are constantly learning new and important facts about evolutionary mechanisms.

--Theodosius Dobzhansky, "Nothing in Biology Makes Sense Except in the Light of Evolution," American Biology Teacher, vol. 35 (March 1973) reprinted in Evolution versus Creationism, J. Peter Zetterberg ed., ORYX Press, Phoenix AZ, 1983

And this from R.C. Lewontin:

It is time for students of the evolutionary process, especially those who have been misquoted and used by the creationists, to state clearly that evolution is a FACT, not theory, and that what is at issue within biology are questions of details of the process and the relative importance of different mechanisms of evolution. It is a FACT that the earth with liquid water, is more than 3.6 billion years old. It is a FACT that cellular life has been around for at least half of that period and that organized multicellular life is at least 800 million years old. It is a FACT that major life forms now on earth were not at all represented in the past. There were no birds or mammals 250 million years ago. It is a FACT that major life forms of the past are no longer living. There used to be dinosaurs and Pithecanthropus, and there are none now. It is a FACT that all living forms come from previous living forms. Therefore, all present forms of life arose from ancestral forms that were different. Birds arose from nonbirds and humans from nonhumans. No person who pretends to any understanding of the natural world can deny these facts any more than she or he can deny that the earth is round, rotates on its axis, and revolves around the sun. The controversies about evolution lie in the realm of the relative importance of various forces in molding evolution.

--R.C. Lewontin, "Evolution/Creation Debate: A Time for Truth," Bioscience 31, 559 (1981) reprinted in Evolution versus Creationism, op cit.

This difference between "fact" and "theory" is an important one because the creationist arguments rarely fail to confuse the forest for the trees--to be so myopic in their objection to the details of evolutionary mechanisms and the fault-finding they engage in--that they slyly divert attention away from what is the real issue. Which is that there is no other logical explanation for the fossil evidence we see without invoking supernatural explanations.

The facts are very simple: If you assume the evidence in the fossil record (not to mention the evidence for, and observable instances of, modern-day speciation) is explainable at all, the ONLY explanation that makes any logical sense is evolution. You have to assume, unless creatures and fossils materialized out of thin air, that parent creatures reproduce child creatures in an unbroken sequence of genealogy from past to present--just like we see today. Given that, there is no other factual alternative than that early fossil forms in the nested and hierarchical succession of changing fossil forms in the geological record gave rise to later ones via some physical route of continuity through ancestry, unless you propose some arbitrary, unexplainable exceptions to physical causation and posit an external supernatural cause.

Again, it really is that simple: evolution is the only physical, factual, explanation there is that makes any logical sense of all the evidence. Even where sufficiently exact explanations for certain phenomena still are lacking and being investigated (perhaps the primary one still remaining is the investigation of the complete suite of mechanisms necessary to fully explain macroevolutionary events), nobody who is interested in logical physical explanations doubts the general coherence of the evolutionary explanation--because there is no other logical physical explanation.

And while it may be true that nothing is ever proven "for certain" in science, still, that evolution occurred is a "fact" of equal merit with the "fact" of a spherical earth orbiting the sun. Remember that for a general acceptance of the most basic outline of evolutionary theory--that later organisms came from earlier ones somehow--not much more than the evidence available in Darwin's day, fossil gaps or not, is all that is needed to show that an evolutionary explanation (whatever the specific mechanisms might turn out to be) is the only logical physical explanation of the evidence possible.

For more on "evolution as both a fact and a theory," see the Talk.Origins link: "Evolution is a Fact and a Theory," by Laurence Moran.


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