Monday, January 7, 2008

Transitional fossils/fossil record


Intelligent design is not science. This fact has never been as clear as it was on December 20th, 2005, in Dover, PA when Judge John E. Jones III declared that Intelligent Design had no place in the science curriculum in the region. In Jones’ words:

"After this searching and careful review of ID [Intelligent Design]
as espoused by its proponents, as elaborated upon in submissions
to the Court, and as scrutinized over a six-week trial, we find that ID
is not science and cannot be adjudged a valid, accepted scientific theory,
as it has failed to publish in peer-reviewed journals, engage in research
and testing, and gain acceptance in the scientific community. ID,
as noted, is grounded in theology, not science." (Brockman 2006 p.252)

The implications of this statement are obvious to anyone with a background in the debate. However, for those individuals unfamiliar with the issue, and also for those individuals desiring to understand exactly why Intelligent Design [ID hereafter] is nothing more than an unintelligently designed challenge to evolutionary theory that clings to Young Earth Creationism [YEC] even when the "Designer" of ID is never identified, an inquiry into the works of the theory’s proponents is required.

That is the intent of this essay; in an attempt to illustrate why ID is a non-scientific idea that is strongly tied to its Creationist heritage, the works of leading ID proponents and also major documents from the ID movement will be considered, and compared to YEC theory. This essay will focus mainly on the ID, YEC, and mainstream science arguments dealing with the fossil record.

Historical background

Ever since Darwin, the fossil record has been cited as one of the best sources of evidence in favor of evolutionary theory. However, many leaders of the YEC movement (Duane Gish for example) point to gaps in the fossil record as "proof" that God created "kinds" of animals that cannot be crossed by evolution; ie. evolution can occur within a "kind", but never between "kinds". What is a "created kind"? You won’t find the answer in many YEC works. However, Of Pandas and People, the textbook that the ID movement has repeatedly attempted to push into classrooms, does indeed offer a definition of a "created kind" within its definition of ID, which, ironically, also nullifies ID’s claim to be a scientific theory:

"Evolutionists object to the view of intelligent design because it does not give a natural cause explanation of how the various forms of life started in the first place. Intelligent design means that various forms of life began abruptly through an intelligent agency, with their distinctive features already intact---fish with fins and scales, birds with feathers, beaks, and wings, etc. "[Davis and Kenyon 1989, p.99-100)

As shown by the quote above, the ID movement essentially gives up all scientific validity within its own textbook by appealing to the supernatural. In fact, during the Dover trial, Michael Behe, one of the leaders of the ID movement, acknowledged the fact that if the rules of science were changed to include ID, by definition astrology would also be considered science (Humes 2007 p. 301).

Also telling with regards to the above quote is the fact that if the term "intelligent design" were changed to "creationism", one would have no problem accepting the quote as being from a YEC publication. Perhaps this is because the book was initially a Creationist textbook initially titled Biology and Creation (Shermer 2006 p. 103). Also worth noting is that the 1989 version of Pandas is the first version of the textbook printed as an ID textbook. The book was printed in 1986 as Biology and Creation.

Anyway, back to the fossil record. The ID movement, in the above passage, appears to claim that evidence of evolution is not to be found in the fossil record. This is a commonly held misunderstanding among ID theorists. While claiming that the fossil record shows no evidence for evolution, they also reveal a major misunderstanding of the way paleontology works.
Other discussions of the fossil record by ID theorists are just as telling. The Design movement, as championed by the Discovery Institute, seems to thoroughly prefer the idea that there are gaps in the fossil record that nullify the fossil record to the idea that most paleontologists hold (the fossil record supports evolution). This is strongly evidenced in the writings of Robert C. Koons in Dembski 2004:

As is well known, the fossil record of the family tree of evolution is so gappy that it consists of a great deal more gap than tree…[Dembski here attests to problems in the invertebrate fossil record]…The missing links that have been found, like the Archaeopteryx or Australopithecus, are better described as mosaics: recombinations of adaptations found in what are assumed to be related families. (Koons in Dembski 2004 p.4)

This blog deals with evolutionary evidences present in vertebrates. The organisms involved are much more well-known to the public than invertebrates are, so it makes sense to consider vertebrates here. Invertebrates will be considered later in these blogs. While Archaeopteryx is called a "mosaic" by Koons, as well as by other Design theorists, it is worth noting that this "mosaic" showcases exactly what one would expect in a transitional form. This idea will be discussed below.


Let us consider the case of Archaeopteryx. While heralded as a perfect transitional form by paleontologists and biologists for more than a century (Thomas Henry Huxley, "Darwin’s Bulldog", used Archaeopteryx and some bird-like dinosaurs such as Compsagnathus to theorize that birds evolved from dinosaurs. This idea was forgotten for decades after his death until it was revived strongly by Bakker and Ostrom in the late 1960’s), the Creationist movement immediately began to call Archaeopteryx "just" a bird, and not a transitional fossil. Indeed, Duane Gish continues with that line of argument even today.

While the classification of Archaeopteryx as "just" a bird is likely partially a product of the Linnaean system (there is no classification for a transitional form between birds and dinosaurs under the Linnaean system, so it is classified as a bird because it is more bird-like than dinosaur-like), it is still used today as an argument against evolution. Jonathan Wells of the Discovery Institute (the main proponent group of ID theory) is militantly against the classification of Archaeopteryx as a transitional form, as shown in his book Icons of Evolution, Science or Myth?: Why Much of What we Teach About Evolution is Wrong. Wells essentially argues that since Archaeopteryx cannot be shown to be an ancestor of modern birds, it does not qualify as a transitional form.

This shows a major misunderstanding of paleontology research, and the classification of a transitional form. Archaeopteryx is a transitional form because it shows both bird-like (feathers, wings, etc) and dinosaurian (teeth, bony tail, etc) features. In fact, until the first feathered specimen of Archaeopteryx was found, the known specimens of Archaeopteryx were instead classified as specimens of the genus Compsagnathus, which was a small bipedal Theropod dinosaur.

However, as conclusive as the evidence in favor of Archaeopteryx being a transitional form is, other ID theorists also misunderstand the basis on which Archaeopteryx is classified as a transitional form. This list includes lawyer Phillip Johnson, who is often credited with beginning the ID movement. While Johnson may be brilliant as a lawyer, he is not qualified to discuss paleontology, as shown by the following passage:

"Archaeopteryx is an impressive mosaic. The question is whether it is proof of a reptile (dinosaur) to bird transition, or whether it is just one of those odd variants, like the contemporary duck-billed platypus, that have features resembling those of another class but are not transitional intermediates in the Darwinian sense. "(Johnson 1993 p. 80)

This passage shows a major misunderstanding as to why Archaeopteryx is considered to be a "transitional intermediate in the Darwinian sense". Archaeopteryx is not considered to show dinosaurian paternity for the avian class merely because it has a few dinosaur-like features. Rather, the fact that the skeleton of Archaeopteryx is similar enough to the Theropod body plan to be mistaken as a small Theropod (Compsagnathus) until feathered specimens were found is why Archaeopteryx is classified as a transitional form. The hips, teeth, claws, shoulders, and skeleton as a whole of Archaeopteryx is essentially dinosaurian. This is why Archaeopteryx is classified as a transitional form, not because of some minor similarities, but rather due to major irrefutable physical similarities between birds and dinosaurs shown in Archaeopteryx. See the National Center for Science Education article cited for an in-depth explanation of Wells’ claims on Archaeopteryx and also the rest of his book.

Dinosaur transitional phases

It is worth noting at this point, while both some ID theorists and also the YEC movement claim that macroevolution is not visible through the fossil record, it is perhaps most visible through some dinosaurian lineages. See for example Ceratopsian dinosaurs. The beautiful thing about the Ceratopsian dinosaurs is the fact that within this group there is present both macroevolution and microevolution, and evidence of both is present. For microevolution, just look at the sacrums of the lineage. It soon becomes obvious that this lineage showcases a trend towards robustness as the Ceratopsians evolve from a bipedal ancestral stock (Psittacosaurus) into a hefty quadruped (Triceratops). The change in habit from biped to quadruped, as well as the appearance of horns through the lineage, seemingly out of nowhere, is proof of macroevolution, and also proof that evolution can indeed "create" information. First, in Protoceratops paleontologists see the appearance of a frill, then in later ceratopsians paleontologists can watch (metaphorically speaking; they use fossils) horns form from regions where no horns were initially present in ancestral forms. Here we have a beautiful example of macroevolution and microevolution working in conjunction in order to form new structures and body plans.

Also worth noting is the fact that not only does Archaeopteryx show us a dinosaurian ancestry for the birds, but also that there are other feathered dinosaurs that show evidence of close relation to birds. These animals include Sinosauropteryx and Caudipteryx, both from China.

Tetrapod/early Amphibian evolution

Other transitional sequences are also present, and often ignored by ID theorists. The most commonly ignored transitional sequence is perhaps the evolution of early amphibians from Crossopterygian fish. With the recent discovery of Tiktaalik rosea, we now have an absolutely beautiful transitional sequence documenting early tetrapod evolution (see for example Shubin p. 82-91 in Brockman 2006). However, a brief survey of some of the major ID works shows yet another misunderstanding of the fossil record in reference to this transitional sequence.
First, let us again consider the 1989 edition of Pandas:

"Evolutionists believe that the first amphibians (the labyrinthodonts[italics in original]) evolved from early fish known as crossopterygians or lobe-fined fish. A very similar lobe-finned fish swims the (sic) Indian Ocean today…[brief reference to figure in book here]…If crossoperygians really did evolve into amphibians, tremendous changes must have taken place. Fins must have been transformed into forelimbs. The skull had to change from two parts to a single, solid piece. The hip bones had to enlarge and become attached to the backbone. As well as changes in the skeleton, not a few changes must have occurred in organs, muscles, and other soft tissues. For example, the air bladder of the fish had to be transformed into the lungs of the amphibian.
Though just a few of the many examples possible, these are enough to show how large the differences between early fish and amphibian really were. How many different transitional species were required to bridge the gap between them? And how many generations of each species must have been involved? Were hundreds or even thousands of species required? We have no way of knowing, but we do know that no such species are found in the fossil record." (Davis and Kenyon 1989 p. 102)

It is worth noting here that even at the time this edition of Pandas was published, there were known transitional fossils bridging the gaps noted here (also please refer to Shubin’s article in Brockman 2006, Icthyostega and tetrapod-like fish were present in the fossil record, and had been discovered. Tiktaalik only filled in yet another gap within that lineage, effectively adding even stronger support to its validity). With the edition of Tiktaalik rosea to this lineage, there is no doubt that we do indeed have a transitional line leading from fish to amphibians and tetrapods as a whole.


When confronted with the problem of the whale transitional series in The Politically Incorrect Guide to Darwinism and Intelligent Design, Jonathan Wells does accept the presence of the whale transitional lineage. However, he attempts to make their presence irrelevant by essentially claiming that since they did not "give birth to the other" that they do not count, and also by stating the following:

"It turns out that the problem with fossils is not that transitional links are missing, but that the fossil evidence in principle cannot provide evidence for descent with modification" (Wells 2006 p. 20)

However, ask almost any paleontologist and you will find out that the fossil record does, by nature, prove evolutionary theory. This passage by Wells shows a complete and total misunderstanding with regards to the fossil record. For a good discussion of the whale transitional fossils we have, check out the article "Hooking Leviathan by its Past" in Gould 1995.


The human transitional sequence is perhaps the most hotly debated transitional series known. This is perhaps due to the fact that this exact lineage directly involves our species as a whole. While many ID theorists (and all YEC theorists) deny the existence of human transitional fossils, the evidence is indeed there in favor of evolution for those who look. Since this is not my area of expertise, see for example Ch. 3 (p. 60-89) in Eldredge 1991 for both detailed yet accessible descriptions and also images, and also Tim D White’s article in Brockman 2006. For internet sources, check out the following: note that Design advocates will not call themselves creationists and make a distinction between themselves and creation science there.
another decent site. google searches will bring up a whole list of human transitional forms.


A brief foray into the field of vertebrate paleontology shows that the fossil record does indeed support evolutionary theory. While there is no time for more discussion in this blog, the fossil record will serve as an underlying theme of all the blogs presented in this series. As shown, many Design theorists tend to support the idea that there are gaps in the fossil record that somehow serve to disprove evolution. While some ID theorists, like Michael Behe, are open to macroevolution and accept the fossil record for what it is, most seem to misunderstand the nature of the fossil record. This is either due to a lack of expertise or a preconceived notion that for their theory to succeed fossils must be ignored. This works in conjunction with one of the Wedge Document’s major goals, namely, to "Replace materialistic explanations with the theistic understanding that nature and human beings are created by God" (Discovery Institute. "The "Wedge Document": "So What?""). This statement in itself shows why exactly Discovery Institute’s science agenda (and therefore, Intelligent Design as a "science") is flawed. Science does not allow appeals to the supernatural, and the Discovery Institute’s Center for Science and Culture expects science to eventually allow these appeals. However, science will stand its ground, and the fossil record will continue to do what it has for the past 150 years; show strong evidence of evolution itself.

Luckily for Darwin, however, the fossil record does support evolution. And unluckily for the Discover Institute, as shown by history, appeals to the supernatural are a science-stopper, and support the mindset of "God did it, no need to understand why". This is the fatal flaw of the Discovery Institute’s Wedge strategy. Science, by nature, excludes the supernatural, and will continue to do so, even if Discovery Institute plans otherwise. Read the Wedge Document (printed in Humes 2007 p. 356-7, and also the Discovery Institute’s "The "Wedge Document": "So What?"") in order to understand exactly what the "Wedge Strategy" is. It will be discussed throughout these blogs.

Works Cited

Brockman, J. Intelligent Thought: Science Versus the Intelligent Design Movement. Vintage Books. NY 2006. Trial transcript in Appendix, also Neil Shubin article p. 82-91.
Davis, P., and Kenyon, DH. Of Pandas and People: The Central Question of Biological Origins. Haughton Publishing Company, Dallas, 1989. The "Intelligent Design" textbook supplement for biology curriculums
Dembski, W. Uncommon Dissent: Intellectuals Who Find Darwinism Unconvincing. ISI Books, Wilmington. 2004 a volume collecting writings of some of the more prominent Design theorists.
Discovery Institute. "The "Wedge Document": "So What?"". Available on this article is the Discovery Institute’s attempt to explain away the Wedge Document, and includes text of the actual document.
Eldredge, N., Fossils: The Evolution and Extinction of Species. Harry N. Abrams, Inc., NY, 1991. One of the best general guides to fossils and evolutionary theory ever published in my opinion. Outstanding images of fossils from the American Museum of Natural History accent a beautifully written book.
Gould, SJ. Dinosaur in a Haystack Three Rivers Press, NY, 1995. Article "Hooking Leviathan by its Past" on whale transitional forms present in this work
Humes, E. Monkey Girl: Evolution, Education, Religion, and the Battle for America’s Soul. HarperCollins NY, 2007. First Edition. Discussion of the recent Dover trial.
Johnson, PE. Darwin on Trial. InterVarsity Press, Downers Grove, 1993. One of the books credited with kicking off the Intelligent Design movement.
National Center for Science Education. "Icons of Evolution? Why Much of What Jonathan Wells Writes About Evolution is Wrong".
this page explains nicely the errors in reasoning of Well’s book Icons of Evolution.
Shermer, M. Why Darwin Matters: The Case Against Intelligent Design. Times Books, NY, 2006. A stinging rebuttal of Intelligent Design that shows its inherent existence outside the realm of science
Wells, J. The Politically Incorrect Guide to Darwinism and Intelligent Design. Regnery Publishing, Inc, Washington DC, 2006. a guide to intelligent design published by Discovery Institute. Read with caution; the work is massively biased.
Wells, J. Icons of Evolution, Science or Myth?: Why Much of What we Teach About Evolution is Wrong. Regnery Publishing, Inc, Washington DC, 2000. Wells’ first major work attempting to disprove some evidence for evolution presented in classrooms.

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