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Of Pandas and People: A Brief Review
Of Pandas and People, which pretends to be an open, objective examination of the pros and cons of evolutionary biology, is actually nothing of the sort. It is, instead, a collection of half-truths, distortions, and outright falsehoods that attempts to misrepresent biology and mislead students as to the scientific status of evolutionary biology.
A complete critique of the many problems with Pandas would take almost as many pages as the book itself, but here are a few points of special concern:
The Age of the Earth
Pandas claims to be a book that seeks to examine the timeless question of biological origins. A truly scientific attempt to do exactly this would begin by examining the age of the earth and reviewing the scientific techniques used by geologists to determine the ages of rocks and fossils. Curiously, Pandas does nothing of the sort. In fact, not a word can be found anywhere in Pandas regarding the age of the earth or geological ages recognized by earth scientists. Ignoring the age of the earth while attempting to teach students natural history makes about as much sense as trying to teach American history without telling students that the American revolution began in 1775, which is to say, no sense at all.
Why does Pandas make this striking omission? Its authors have never been willing to say why they ignore such a crucial part of earth history, but I suspect that the answer is simple. If they were to bring authentic scientific evidence regarding earth history into play, it would immediately become clear to readers that the ages of rocks and fossils support, in dramatic fashion, the evolutionary history of life that geologists have recognized for many decades. Because this important mass of scientific evidence is at odds with their anti-evolutionary thesis, they choose to ignore it. They are free to do this, of course, but students who might attempt to use Pandas as a scientific textbook will be rightly baffled by its attempts to teach natural history without a time scale, and will surely ask their teachers what science can tell us about the geologic time scale. Pandas, for reasons of its own, chooses to duck this most basic question because it does not like the answer that science provides.
The Fossil Record
Pandas seriously misrepresents the nature of the fossil record. For example, on pages 99-100 the authors of Pandas have written:
"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. Some scientists have arrived at this view since fossil forms first appear in the rock record with their distinctive features intact, rather than gradually developing."
Actually, a close examination of the fossil record supplies scores of examples that show the gradual appearance of a wide variety of physical adaptations, including, for example, the vertebrate limb. Pandas wishes to claim that abrupt appearances of critical features (which might be taken to support design) characterize the fossil record. Unfortunately, this contention does not square with the facts. The earliest known fish, for example, were quite different from the fish we recognize today. The earliest fossil forms lacked many of the characteristics possessed by fish today, including jaws, paired limbs and bony internal skeletons, and yet Pandas wishes to tell students that fish (and all fossil forms) appear in the fossil record "with their distinctive features intact."
To take another example, strong fossil evidence indicates that the first land vertebrates evolved from lobe-finned fish. One of the very first land vertebrates, a species known as Acanthostega gunnari, illustrates the point. Acanthostega, although clearly a land-dwelling animals, retained an unmistakable sign of its aquatic ancestry: internal gills. No other amphibian possesses internal gills, and the gills preserved in key Acanthostega fossils make it clear that Acanthostega could breathe with its gills underwater, just like a fish, and could also breathe on land, using lungs. In other words, it was a true "transitional form." This first amphibian-like tetrapod was, as evolution would have predicted, more fish-like than any tetrapod to follow. As the discoverers of one of the most detailed Acanthostega fossils wrote: "Retention of fish-like internal gills by a tetrapod blurs the traditional distinction between tetrapods and fishes." (MI Coates & JA Clack (1991) "Fish-like gills and breathing in the earliest known tetrapod." Nature 352: 234-236.).
Pandas implies that fossils such as these have never been discovered.
More to the point, in 1998 paleontologists Edward B. Daeschler and Neil Shubin discovered a fossilized fin so well-preserved that its soft parts could be seen outside its underlying bony skeleton. The fin contained eight well-defined, recognizable digits. Incredibly, this fish had a fin with fingers, eight in number, just like the digits of Acanthostega. In other words, the limbs of land vertebrates did not appear suddenly (as if designed). They began to appear gradually, in the ancestors of land vertebrates, as if they evolved. (See: "Fish with Fingers?" Nature 391: 133 ). If Pandas' goal was to engage students with authentic data, rather than to raise doubts and questions in the minds of its readers, it would surely present and discuss these fossil forms. Instead, it offers students a generalization that such fossils do not exist. Unfortunately, that generalization is wrong.
More Misrepresentations of the Fossil Record
On page 95 of Pandas, Figure 4-2 attempts shows the abrupt appearance of most phyla in the Cambrian Period of geological history. Curiously, the diagram is a schematic, not a genuine diagram in which the individual phyla would be labeled and identified. Why not show the actual phyla and their names? I believe the reason is very simple. If the phyla were all labeled, the authors would not be able to make the suggestion that they do now, which is that most important groups of organisms alive today can trace their origins to this period, nor would they be able to pretend that all multicellular animal life first appeared in the Cambrian. In fact, if the dominant forms of plant and animal life on land were included in such a diagram (flowering plants and insects, respectively), students would learn that these organisms appeared hundreds of millions of years after the time shown in the graph. Furthermore, all of the great unicellular phyla (found in the kingdoms Eubacteria, Archaebacteria, and Protista) precede the Cambrian by hundreds of millions of years. And finally, the animals of the Cambrian were preceded by abundant soft-bodied animals known as Ediacaran fauna, which date at least a hundred million of years back into the Precambrian. Unfortunately, the readers of Pandas will never learn these facts because the authors are so intent on pretending that all major groups of organisms originated at just one period of time. And that is simply not true.
Pandas Ignores the Issue of Extinction
Pandas shows a remarkable unwillingness to address the obvious questions raised by its own theories. For example, on page 99 (Figure 4-4) a graph showing a "face value" interpretation of the fossil record is presented. It looks something like this:
What question would any inquisitive 9th-grader ask of this graph after being instructed in "intelligent design" theory? Just this: If all organisms are intelligently designed, what are the forces that seem always to intervene and drive these organisms to extinction? Any theory that claims to see intelligence in these designs that have mysteriously appeared in living organisms over millions of years must also explain why these designs seem to fail nearly every time. Evolution, of course, can explain extinction quite easily. In fact, extinction is a major evolutionary mechanism. But Pandas avoids this embarrassing problem. Its authors cannot explain extinction, and therefore they short-change their student readers by stepping around the question.
The Predictions Made in Pandas are Dramatically Incorrect
Pandas' predictions about future discoveries of fossils are wrong. To be sure, the text makes very few statements that could be subjected to scientific testing. However, when it does make a prediction, it fails miserably. Consider this statement from Pages 101-102:
"The absence of unambiguous transitional fossils is illustrated by the fossil record of whales. The earliest forms of whales occur in rocks of Eocene age, dated some 50 million years ago, but little is known of their possible ancestors. By and large, Darwinists believe that whales evolved from a land mammal. The problems is that there are no clear transitional fossils linking land mammals to whales. If whales did have land-dwelling ancestors, it is reasonable to expect to find some transitional fossils. Why? Because the anatomical differences between the two are so great that innumerable in-between stages must have paddled and swam the ancient seas."
Yes, evolution predicts that there should have been transitional forms linking swimming mammals with land mammals. And their absence, Pandas argues, is good evidence that evolution is wrong. Well, guess what? In the past 10 years not one, not two, but three true intermediate forms have been discovered. Up until 1986, the oldest known fossil whale had been Basilosaurus, dating to about 40 million years before present (a sketch of Basilosaurus is shown in Pandas). However, fossil-hunters have now found 3 intermediates that link Basilosaurus to land-dwelling ancestors. They are:
Pakicetus inachus — 52 myr.
Ambulocetus natans — 50 myr.
Rodhocetus kasrani — 46 myr.
The actual fossil forms were described in a 1994 article in the journal Science (JGM Thewissen, ST Hussain, M Arif (1994) "Fossil evidence for the origin of aquatic locomotion in archaeocete whales." Science 263: 210-212.). A less technical account of these intermediate forms and their importance for understanding cetacean evolution was written by Stephen Jay Gould in Natural History magazine ("Hooking Leviathan By Its Past," Natural History (April 1994), p. 12).
Pandas, in teaching students that such intermediate forms would, indeed, could never be found, compounds its earlier misrepresentations of fossil history with an outright falsehood, a misperception of reality which has no place in authentic scientific education.
Pandas misrepresents the Molecular Evidence for Evolution
Pandas' entire Chapter 6 (on "Biochemical Similarities") is based on an incorrect representation of evolutionary theory. I don't know if it was done intentionally or out of simple misunderstanding, but either way, I would argue that the errors in this chapter as reason alone to disqualify the book for use in the science classroom.
Basically, the chapter states again and again that evolution predicts that amino acid sequences of key proteins (like cytochrome c) should be arranged in a linear sequence. For example, if one takes the sequences of, say, a worm, a frog, and a human, the frog sequence should be closer to the worm than the human sequence is. That is the claim that Pandas makes repeatedly as a "prediction" of evolutionary theory. However it is simply not true that any evolutionary biologist has ever made such a prediction (significantly, Pandas does not cite any references for its claims). Pandas then examines the data and shows that the frog and human sequences are equally distant from that of the worm. That, it argues, is contrary to the evolutionary prediction.
This is simply not true. I honestly do not know if the authors of Pandas intentionally misrepresented evolutionary predictions or if they simply did not understand them. However, the real story is that the fossil record clearly shows that the entire vertebrate group (including frogs and people) split off from the invertebrates (including worms) many hundreds of millions of years ago. Therefore, the protein sequences of every animal in that group should be equidistant from any single invertebrate. And that is exactly what the experimental data show, as the authors of Pandas ought to know.
The simple fact is that this chapter misrepresents evolutionary predictions on molecular sequences, and thereby covers up the fact that the sequences stand in stunning agreement with evolution. I cannot even imagine a greater misrepresentation of fundamental data to support an incorrect conclusion.
I could go on to document further misrepresentations of scientific fact and theory in Of Pandas and People. However, my criticisms of this text are not unique. In fact, the many errors and misleading statements in this text were immediately recognized almost from its first publication by a variety of scientists and educators. Reviews describing the errors and misrepresentations in Pandas have appeared in many publications, including Scientific American (July 1995, Science and the Citizen, "Darwin Denied").
Science is an open enterprise, and scientific inquiry thrives precisely because no scientific theory or idea is ever immune from criticism, examination, or testing in the crucibles of experiment and observation. When I first opened the pages of Pandas and read the fine words presented by its authors in the name of free and open inquiry, I expected a text that might genuinely challenge students to examine the assumptions of what they had learned and evaluate scientific theory in an objective manner. To say that I was disappointed is to put it mildly. What I found instead was a document that contrived not to teach, but to mislead.
Pandas mis-states evolutionary theory, skims over the enormous wealth of the fossil record, and ignores the sophistication of radiometric dating, How sad it would be, given the need to improve the content and rigor of science instruction in this country, for this book to be offered as part of the educational solution. There is a great deal that we do not know about the origin of life on this planet, but that does not mean that science is obliged to pretend that it knows nothing, or to engage in a kind of scientific relativism, pretending that all speculations about the origin of our species are equally correct. The most compelling reason to keep this book out of the biology classroom is that it is bad science, pure and simple.
Science education today faces many challenges. Our teachers must deal with an ever-changing landscape of scientific advance and technological innovation that continually changes the ground upon which they educate their students. Biology education, in particular, will be the key for many of our students as they attempt to prepare themselves for the challenges of the next century, and therefore it is especially important that teachers be supported, not hindered, in their attempts to educate students in the life sciences. The many errors and misrepresentations that inhabit the pages in Of Pandas and People will, quite honestly, serve to hinder teachers as they attempt to cover the stunning range and diversity of contemporary biology. I believe it is best not to burden science faculty with the needless task of overcoming the many errors and misconceptions written into this book.
Kenneth R. Miller
Note: Reproduced by permission of Kenneth Miller. Minor typo corrections and formatting for the NCSE website performed by Nick Matzke. This article was originally published on the Kansas Citizens for Science website in 1999: http://www.kcfs.org/pandas.html