Kitzmiller v. Dover Area School District
Trial transcript: Day 9 (October 14), AM Session, Part 2
THE COURT: All right, Mr. Walczak, you may continue.
MR. WALCZAK: Thank you, Your Honor.
Q. Dr. Padian, what is intelligent design?
A. As I understand the definition, intelligent design is the proposition that there are some things, natural phenomena in the world that could not have come to being by natural means and that the design of these structures has a certain complexity and certain features that implies that they must have been produced by what is called an intelligent designer by which is understood to mean possibly some kind of unknown forces or a supernatural being.
Q. And how is intelligent design different from creation science?
A. Well, it has some similarities, and it has some differences. Creation science is a movement that flowered mostly in the 1960s and 1970s. And creation science was an attempt by certain conservative Christian people with some science or engineering degrees to attempt to explain Bible stories or to find scientific evidence for Bible stories or explain them in scientific terms, that is, to attempt to justify them on scientific grounds.
Intelligent design doesn't have as its objective to validate Bible stories or any particular religious or creation stories, but what it shares with creation science, in part, is the insistence that things were designed and could not have evolved. And so over 90 percent of the corpus of intelligent design work has to do with basically trying to undermine the evidence for evolution and the concepts associated with evolution and related sciences.
Q. And we're going to spend a good bit of time talking about the undermining attempt, the undermining of the evolutionary science.
As I understand it, the affirmative argument for design, not the criticism of evolution, but the affirmative argument for design is that it looks designed or it's so complicated we can't imagine that it couldn't have been designed. Is that your understanding?
A. That's my understanding, in an informal sense, that that's what they mean.
Q. What's wrong with this appearance of design analysis from a scientific standpoint?
A. Well, it's not particularly rigorous. Lots of things look designed, but they may not necessarily be designed. Intelligent design looks a lot like science in some respects, but it's only superficial. It doesn't operate according to the principles of science, so the resemblances are superficial.
And appearances can be deceiving. For all the world, it looks like, you know, to us normal people, that the sun goes around the Earth. And for most people, it wouldn't make a difference whether the sun went around the Earth or it went around the moon, as Sherlock Holmes famously said to Watson. But when the renaissance scholars understood, found out that, in fact, the sun does not go around the Earth but the Earth and the planets go around the sun, it changed the way we look at the whole natural world in a very important and fundamental way.
And so part of the process of science is to discover things that will make a difference to our understanding of the natural world and not simply to reinforce appearances that are very difficult to test in an objective or testable sense.
Q. Let's begin to talk about the problems that you have with how intelligent design represents science, and I want to focus on the areas of science within your expertise. What is wrong with the intelligent design arguments against evolution?
A. Well, there are a number of systemic problems with the arguments about intelligent design.
Q. I'm sorry, Professor Padian, have you prepared an exhibit to help you explain this?
A. Yes. At your request, I've done some demonstratives that I hope may be of use in illustrating some of these things.
Q. Matt, would you put up the first slide, please.
A. There are certain systemic problems with the way that intelligent design represents the scientific findings of the scientific community. And in a sense, it is really just standard anti-evolutionist special creationism. I will explain why it's special creationism in the course of things.
The ways that scientists have problems with intelligent design literature is, first of all, that it provides some misleading definitions of evolution. In doing so, it sets up a straw man. It also distorts some commonplace scientific concepts, and, as a result, it sows doubt in the minds of students who would understandably be confused, as I am, by their treatment of certain fairly standard ideas. When they --
Q. What kind of concepts do they sow doubt about?
A. Well, they begin -- if you want to begin with definitions of evolution, they define micro and macroevolution in different terms. Microevolution they're fine with. That's evolution in populations. It's just genetic variation. And creation scientists didn't have a problem with that stuff, either.
But when we study evolution, we actually look at it on several discrete levels. Microevolution is what happens in populations at the gene level and among individuals in populations within a species.
But then when populations diverge from each other geographically and genetically to the point where they become different species, different lineages that are not going to have a mixed history anymore but separate histories and diverge further and make more new species, we call this process speciation, and it's a different level of consideration than simply what happens in populations, because now you see we have the situation where we're no longer exchanging genes with each other in a population, we're actually looking at two separate or more separate entities that will be that way historically for the future.
Once we start looking at how these new lineages, new species and new species that they give rise to, interact in the environment, how they change further through time, how they adapt more to changing environmental conditions, we're now at the level that's called macroevolution. And the reason we call it macroevolution is it's just on a bigger level. We're no longer dealing with populations.
Q. And by "populations," you mean, like, people or horses or --
A. Well, like just groups of organisms. Individual organisms within a species are different populations. You can have a population in this valley, a population in that state, whatever it happens to be.
The way that scientists regard this is much like economists look at microeconomics and macroeconomics. Microeconomics is how you run the corner grocery store, you know, what the economic balance is in the small town's economy, how a company works. But macroeconomics has more to do with things like the Federal Reserve, the international balance of trade. The common thing that -- the thread between this is, of course, money. It's all about currency. It's cash at some level.
And with evolution, we've got genes that are very similar because everything is hereditary. It's transmitted. And the genetic transmission of this works one way within populations when organisms can exchange genes, but when you get above the species level, they're no longer exchanging genes. We're working at different species disporting themselves through time. And then you get the whole process of the evolution of new adaptations and major groups of animals and plants.
And the intelligent design people define macroevolution as a major change that has to happen to make a major group, and they say that this is a completely different process than what happens at the microevolutionary level. And scientists just don't think so.
Q. And are some of the other concepts that they don't quite represent accurately homology and cladistics and classifications?
A. Yes, the basic principles of classification, the principles also by which you can compare organisms in order to say things in comparative biology are very problematic for intelligent design creationists. They have a hard time explaining these in the terms that scientists use. And so a lot of what they do is to try to cast doubt on the very legitimacy of the basis of doing these things as scientists understand them.
Q. I'm sorry, continue. I believe you were on Number 3.
A. One of the problems with the ways that intelligent design creationists present scientific evidence is that they present only part of it. They present the part that might suit their cause, but they really leave out an awful lot of important research. And in so doing, they say that scientists don't know this or they can't know this. And this creates the sense of ridicule for students.
Now, you know, we'll be the first people to admit that science doesn't know everything and can't know everything. But on the other hand, we would like a fair and accurate representation of what we do know.
I would also like to show in the course of explaining some of these things today that most of the claims that the ID proponents make are directly inherited from the old-time scientific creationism claims in the evolution bashing that they do. Many of the same arguments are used, the same kinds of evidence are used.
And, finally, the conclusion that is raised is that if you can mount some kind of alleged evidence against evolution, which is most of what the ID proponents do, as the scientific creationists did, then this is evidence for intelligent design. In so doing, they set up this false dichotomy or contrived dualism of religion and science that is disturbing to scientists who have religious backgrounds, as well as to those who don't have religious backgrounds because it isn't part of science to do that.
Q. Now, you said that ID proponents mischaracterize evolution as just a starting point. Matt, could you put up the next slide.
A. Yes, calling macroevolution the origin of new types, this is not a definition that scientists would recognize. Macroevolution, as I mentioned, is looking at the patterns and processes of organisms above the level of species.
So we're trying to figure out a lot of the major patterns of evolutionary change, but the origin of new types, again, that word "origins" comes in, and scientists just don't talk about origins in that sort of cataclysmic sense.
The proponents of intelligent design, as you see here embodied in these quotes from Of Pandas and People, claim that it's a mistake to claim from macroevolution the status of fact. And, again, this confuses for students what facts mean in science.
In contrast, from Pandas, again from Page 99 to 100, they state, quote, that intelligent design means that various forms of life begin abruptly through an intelligent agency with their distinctive features already intact. And this tells you two things, first of all, that everything was already the way it was when things first appeared, so there's no transitions, and that an intelligent agency did this.
Now, that's a perfectly fine idea, but it's not scientific to claim this in advance of any kind of evidence that could be adduced to the contrary.
Q. But in order for this to be true, you have to show that evolution is false?
A. Yes, or at least you have to exclude the possibility of considering it in advance, which is a philosophical rather than an empirical consideration.
Q. If we could go to the next slide. You say that there are other definitions that intelligent design proponents confuse.
A. Yes. I would just like to clarify what we mean when we talk about speciation, macroevolution, which really differs from how it's treated in texts like Pandas. We call speciation what happens when new lineages are formed. They diverge from parent populations. That is, from old species new species bud off, if you will.
And this can happen in many different ways. You can have changes in behavior, in structure, in ecological adaptation, in physiology, in geography, and all these things may lead to the historical differentiation of these lineages. That's how we get new species. It's been happening ever since life was first running around on the planet.
Intelligent design proponents claim, for example, in Pandas that when speciation occurs, it actually limits variation, and so it's really unlikely that the kinds of changes we see in populations can actually lead to speciation.
I find this statement surprising because there's no evidence that I know of that when a new species forms, that genetic variability is necessarily reduced. It doesn't seem to be the case. Species that are closely related to each other, you don't find one with a lot less genetic variability than another that has ascribed to this process.
And so we regard speciation, in fact, as the raw material for the big changes through time. It's like births in a population are the starting point for populational change and development and the way that new species are formed. Without new species, we wouldn't get any kind of new developments in evolution.
Q. And that's contrasted with macroevolution how?
A. Well, the macroevolution -- then the speciation becomes the raw material for macroevolution, because macroevolution would be the study of what happens to those species after they're formed and as they deploy themselves through time, space, and ecology.
Q. And, Matt, if you could turn to the next slide. And you're familiar with the textbook Of Pandas and People?
A. Yes.
Q. And do you believe that Pandas is a good representation of intelligent design theory or thinking?
A. I think it is. And I believe that the ID proponents also attest to this.
Q. And here we have a slide. We pulled out a passage from Page 85. This is what they say about speciation?
A. Yes.
Q. And could you read the highlighted passage?
A. The whole thing?
Q. Please.
A. It says, Does speciation fit with the theory that species were originally designed? If the intelligent design explanation is true, there may be species on the face of the earth that have undergone no substantial change since their beginning. On the other hand, the idea of intelligent design does not preclude the possibility that variation within species occurs or that new species are formed from existing populations as illustrated by the previous discussion of squirrels. The theory of intelligent design does suggest that there are limits to the amount of variation that natural selection and random change mechanisms can produce.
Q. So according to intelligent design, speciation is what?
A. Well, speciation is, for them, mostly unlikely on the basis of the kind of genetic variation that occurs. They're happy with genetic variation occurring within species. That's perfectly okay with them. That doesn't lead to much of anything. They say that speciation can occur, but it doesn't involve new innovations and that some species have not changed since their beginning. Now, we'll have to examine what we mean by "some."
But they do state that the known natural mechanisms are too limited to account for the important biological change and the adaptive diversity that we see through time.
Q. And if science's concept of speciation is, in fact, accurate, then that would mean that there's no abrupt appearance of organisms already intact?
A. Well, it certainly would mean that we are not finding new complex adaptations appearing all at once in major groups of organisms with no possibility of their evolution step by step from other kinds of creatures out there, and that's a point on which books like Pandas is quite adamant. They consistently say this does not occur.
Q. And is this argument from Pandas and by intelligent design proponents similar to the argument that creation scientists made?
A. Yes. It's quite similar in its ramifications.
Q. Could you put up the next slide, please, Matt. Could you tell us what this is, Professor Padian?
A. The slide is some text from a publication from the Institute for Creation Research called Impact Number 43 by Duane Gish. Duane Gish is vice president of the Institute for Creation Research, a famous creation scientist speaker who has been giving presentations against evolution for several decades now.
And what I'd like to show by this quotation included in the record is that the ideas of intelligent design reflect exactly what special creationists, what scientific creationists, so-called, were saying decades ago.
Here, for example, outlined in yellow on the top paragraph, Duane Gish says that natural selection would be powerless to generate increasing complexity and to originate something new or novel and thus powerless to change one kind of animal into another.
Now, by that is understood, at least, the basis of speciation, and this is very close to what the Pandas text says, and I think the idea really conveys the same message. In the bottom paragraph, Mr. Gish notes that such a process could only produce variance within an established kind and could never produce new and novel structures.
Q. I want to start talking about some of the areas of evolutionary biology and evolution that Pandas discusses and get your understanding of whether they are accurate representations of current scientific thought.
I've asked you to pick several examples out of Pandas where you believe that they do not accurately represent the science. And does the first one involve something called cladistics?
A. Yes. I wanted to talk a bit to explain, if I could, the basis for classification in science.
Q. And when you say "classification," what do you mean by that?
A. I mean precisely how we study the relationships of organisms. The basis of classification, since Darwin, has been the relationships that organisms have to each other.
And the concepts of how classification is done, how we, in other words, understand and construct the tree of life, the whole idea of who ancestors and what ancestors are and the relationships of organisms to each other are problems that works such as Pandas really do not reflect accurately the way that science understands these processes, procedures and methods.
Q. And have you prepared a demonstrative exhibit to help explain this?
A. Yes. I'd like to do just a basic showing of what some of the principles are, if I could have the next slide to talk about that. In their texts, intelligent design proponents either do not understand or they don't accept how scientists establish relationships among organisms because most of this is left out of what their discussions are.
Despite a lot of popular impression, when we try to establish relationships among living and extinct organisms, it's not a never-ending search for direct ancestors. We don't go out in the fossil record, I don't go out looking for dinosaurs or whatever I'm doing in the summer in the field season looking for the ancestor of something else I know. I don't expect to find a direct ancestor of anything. The chances of that are really small. But I want to show you what we do try to look for.
Paleontologists, in other words, are not searching the rocks for the missing links. Instead, when we, like all biologists, establish organisms, living and extinct, whether we work on bacteria or mosses or hoofed animals, it doesn't matter, we all do this according to the same methods in biology, and it doesn't matter whether we use molecules or fossils.
What we do is we look for shared characteristics. These are uniquely shared characteristics shared by certain organisms and not others. And by identifying these characteristics, we identify the pathway of evolution, that is, the order, the sequence, the genealogy of evolution. We want to find out who is most closely related to whom.
And the reasoning is that if an organism acquires a new trait and passes it on to its descendents, then those descendents will be more closely related to each other because they possess that new trait than anybody else in the world will be. And that's the principle that we use.
And this is a fairly simple concept to get across, and it's revolutionized the way that people do what we call systematics or to assemble the tree of life. But, in fact, this began in the 1960s and 1970s, and so for decades it's been the standard.
There are two concepts of ancestry that are important to point out here. One is lineal, and the other is called collateral. Lineal ancestors are the ones that are directly in your path, that is, your parents, your grandparents, your great grandparents, your great, great, great, and all the times you can say great, those are your direct ancestors.
But collateral ancestors are a little broader than that. They would include your aunts and uncles, your great aunt, your cousin twice removed on your mother's side, and that guy with the funny hat in the civil war picture on the wall in the dining room, whatever it happens to be. These are what we call collateral ancestors. They are individuals who are not directly in your ancestral line, but they still share so many of your features that they can tell us a lot about who you were -- who you are.
If you know, for example, that your family came from Sweden in the 1800s, you can return to Sweden to the approximate place where they came. Maybe you can't find their bones in the church yard, but you can find the relics and the remains and the museum's evidence for many other aspects of their culture and their biology. You know what they ate, you know what they wore, you know the language they spoke. You may know from photographs and drawings what they looked like, what their features were. You may be able to recognize your ancestral features, as well. All these things are properties of collateral ancestors, not just lineal or direct ancestors.
So when we look to assemble the relationships of organisms, we don't have to find every direct ancestor. In fact, in the fossil record, it's really hard to say that somebody was anybody's direct ancestor, as I mentioned before with the fossil clams. We don't know what offspring any individual left. It's too hard for us to figure out. But we can still tell a great deal about it. And this is how we assemble the tree of life.
The next slide I have here is a preparation of a kind of diagram that we call a cladogram. And it's very similar to a phylogenetic tree, that is to say a tree of relationships. But the logic of this, I want to point out, is not something that's arbitrary. It's not simply assembled by art or by anything that's subjective. Rather, it is a diagram that reflects the grouping of organisms according to these new evolutionary features, these shared characteristics I mentioned before.
And if you can see the red marks along this -- the basic spine of the hat rack running from the lower left to the upper right -- these things always look like hat racks to me. I don't know what else you'd describe them as. But each one of those red bars represents a feature that was a new evolutionary feature that we reasoned was a new evolutionary feature because it suddenly is something that now all the animals above it share and the animals below it do not share.
So, for example, at the top here, the human and gorilla are united by a great many features, and we've only listed a few here because it would just really crowd things, and I think it's fairly obvious. Things that the human and gorilla share are a prehensile hand and a large brain. That is not the case for the cow, the lion, the marsupials, and the other animals on this slide.
We reason that on the basis of this and many other shared characteristics that these features were inherited from a common ancestor. It's the best natural explanation we can come up with. And as we go down this diagram even more, what we find is that at each juncture -- and if we can just stop it there for a second -- we find an increasing number of things that all these groups have.
And so if you look at the level put here on the chart that's indicated, there's a shared feature called an amnion, which is a property of one of the membranes of the egg around the embryo, that is shared by birds, marsupials, and placental mammals, but frogs and sharks and fishes don't have it. And so these hierarchically nested sets of features are the logical structure by which scientists establish the relationships of life.
Q. I'm sorry, Professor Padian. Matt, if you could go back just a couple of slides. So you talked about how -- and I guess we read from left to right up the line is how you read this?
A. Well, all we can say is this is a depiction of how all these organisms are related. We don't look on this as a ladder of life. We don't look at it as fish give rise to frogs which give rise to birds. It's not like that.
Q. But, for instance, where you have the stirrup-shaped ear bone --
A. Yes.
Q. -- and you have that line, so it would be the organisms above that that share that particular feature?
A. That's correct. That would be something that unites them to the exclusion of all the other critters on the slide. And that's the logic of cladograms, pure and simple.
I'd like to stress that we can use physical features like this, we can use them on fossils or on living animals, we can use them on molecules or we can use them on skeletal features or egg shell proteins or anything else that we want to do. Whatever works, we use. It's very practical.
Q. And is this a -- could you say it's a universal approach used by scientists?
A. Since the 1960s, it has become the dominant form of understanding relationships in the scientific community around the world.
I would go so far as to say that if you were going to apply to the National Science Foundation to ask for money to work on the classification of a group of organisms, whether it was dinosaurs or a group of bacteria or mosses or liverworts, you would have to show the review panel that you understood the principles that I'm discussing here and that you were going to use this kind of analysis in your work if you wanted to convince them that you knew what you were doing.
Q. And is this method somehow validated quantitatively or statistically?
A. Yes. And I'm glad you raised that point, because I've only put a couple of the features on this chart. But, in fact, there are hundreds that are represented in this analysis. And it's obviously too many for us to arrange by hand.
And so all the characters that we're talking about and all the animals that we're trying to analyze, we have ways of putting these into a data matrix and asking the computer essentially to sort this out for us to produce the simplest to the most, basically, complicated trees that you could possibly get. And we try to start with the simplest trees for further work, which is a principle in science called parsimony.
Q. And do intelligent design proponents use this type of cladogram?
A. I haven't seen them use any type of analysis like this in any of their works.
Q. And if you could advance to the intelligent design slide. Is this a copy of a chart found in Of Pandas and People?
A. Yes. This is Figure 4 from Pandas, second edition.
Q. And can you tell us what this is?
A. Well, the caption says that it's the pattern of phylogenetic origins, according to the face value interpretation of the fossil record.
Q. And can you make heads or tails of this?
A. I have trouble. I'm not sure -- I guess I understand that time is the axis from top to bottom. That's perfectly fine, although there are no particular periods listed. I understand that they're looking at variation in morphology, and that's perfectly fine. But there are no names of organisms there, so I don't know exactly what they're talking about.
Also, the presence of these bars as straight bars without variation suggests quite strongly that organisms suddenly appear quite recognizable as what they are and do not vary in morphology all the way up through the geologic column until they peter out.
Q. So this chart would show that there's abrupt creation and then there's no change in those organisms throughout their lifetimes?
A. That would be the face-value interpretation that they say the fossil record shows. Now, I just want to point out that this implies that there is no substantial change in any fossil lineages because they have drawn only bars that go straight up with no change, no diversification, no anything.
Q. And if you represented a classification system in a grant application to the National Science Foundation like this, you don't believe you would get a grant?
A. Well, no, but, of course, this is not meant to represent any kind of research, it's meant to be a didactic device for teaching. I should also note that if we're talking about phylogeny in relationships, this wouldn't qualify because it doesn't draw any lines between those lines. It doesn't admit the possibility that any of those lines evolved from any of the others.
Q. I'm going to talk about the use of the term "irreducible complexity" and "adaptational packages" as it's used by intelligent design proponents.
Can you explain to us how Pandas uses the term "adaptational packages"?
A. Well, the last slide showed you lineages of organisms that seem to have a sudden appearance and no substantial change during their histories and of no relationship to any other lineages in this diagram.
This suggests quite strongly, and the Pandas authors are making this point, that organisms that they regard as major types of organisms suddenly appear with all their major features intact and that they do not change. These are characterized in works like Pandas as adaptational packages, which they say cannot be separated into simpler components without destroying the functional advantage that they provide to the organisms that have them.
And so these adaptational packages for ID proponents represent the concept called irreducible complexity, which means that they can't evolve by known natural means, they're too complex to do so, and so they must be specially created by a designer.
Q. Now, that term "irreducible complexity," is that one, to your knowledge, that's found in Pandas?
A. To my knowledge, the exact words are not found in Pandas. I believe the first place where that is really brought out as a major term is in Michael Behe's book Darwin's Black Box in 1996. But in 1993, when I believe Professor Behe was working on the second edition of Pandas, these concepts are brought out in the second edition of that text.
Q. So Dr. Behe's concept of irreducible complexity is contained in Pandas even though that term is not used?
A. Yes. And before, even in the first edition, these adaptational packages are represented. They are essentially one of these ideas that, again, has a long pedigree, that there are such complex forms out there they couldn't possibly have evolved. We've heard these arguments since the 1800s, so they do have a long history.
Q. Perhaps you could help explain to us these adaptational packages and irreducible complexity.
A. Well, there seems to be some conflict among the ID proponents about this. Dr. Behe claims that irreducible complexity applies only to cells and molecules, and that's his specialty, of course, he's a biochemist, and that it does not apply to adaptive features in organs or to major groups of organisms.
But if you look at the whole corpus of intelligent design work, including Pandas, on which Dr. Behe worked, the implications of irreducible complexity are extended time and time again to large-scale tissue and organ adaptations and, indeed, to whole organisms.
And so if we're going to accept this, we have to accept that Dr. Behe had no knowledge that his coauthors were going to take his concept above the cell and molecular level, or irreducible complexity is, in fact, not only a molecular concept and we cannot accept Dr. Behe's view on that point.
Q. And have you identified an example to show how this irreducible complexity does apply above the molecular level?
A. Yes. I'll give a number of them from Pandas just to show that they actually are there. The next slide, I believe, shows several quotations from Pandas that indicate that it applies to levels above simply molecules. A quote from Page 72 indicates that multi-functional adaptations where a single structure or trait achieves two or more functions at once. This is not restricted to the cell level.
A quote from Page 71 talks about, quote, the total engineering requirements of an organism like the giraffe, unquote. So here they are talking about the whole organism, a giraffe, not simply a cell or a molecule.
The quote from Page 66 says, quote, It has not been demonstrated that mutations are able to produce the highly-coordinated parts of novel structures needed again and again by macroevolution.
Now, recall here that macroevolution, to intelligent designers, is the origin of new types of organisms, not of new cells, not of new molecules. So they are really looking at the large-scale structural tissue, organ, individual organism level. And, finally, the quotation from Page 25, which I believe is maybe even repeated more or less on Page 99 --
Q. So that's not an error, that is on Page 25?
A. Oh, yes, it's 25, as well.
Q. And this is from the introduction, overview of the book?
A. Yes, it's from the overview of the book. It says, quote, that design theories suggest that various forms of life began with their distinctive features already intact, fish with fins and scales, birds with feathers, beaks, and wings, et cetera. So they are talking about various forms of life, not molecules, not cells.
And here's an example, just to show you a page from Pandas, that does this with respect not to the giraffe as a whole, I've already showed you how they've dealt with the consummate engineering requirements of the giraffe as a whole, but this is just a set of structures in the giraffe's head, neck, and brain.
Q. And could you identify the figure and page number?
A. Oh, yes, I'm sorry. This is Figure 2.5 from Pages 69 and 70.
Q. And that's in Pandas?
A. In Pandas, second edition. And so they are talking about an adaptational package in the caption that protects the giraffe from hemorrhaging in the brain. And this is all perfectly reasonable. Pressure sensors along the arteries, muscle fibers in the artery walls, heavily valved veins, and the arteries that approach the head they say correctly branch into what's called rete mirabile, which is a network of capillaries that prevents the brain from exploding when it gets a flood of blood coming up to it suddenly.
These are correctly understood by physiologists as part of an adaptation of the giraffe, but I just want to point out here that this is not a discussion of cells and molecules, this is a discussion of tissues and organs.
Q. Now, I want to turn to the fossil record, and I've asked you to identify from the book Of Pandas and People various examples where they claim that certain types of organisms could not have evolved naturally.
Can you show us where you believe that Pandas misrepresents the science? I believe you want to start with the Cambrian explosion?
A. Well, I'd like to start with a few examples that are of some concern to scientists because the representation of the science in these pages is really quite different from what scientists understand and understood when Pandas was written.
The next slide, I guess, starts with several quotations from Pandas about the Cambrian explosion. Now, I should explain that what is meant by the Cambrian explosion is a sudden appearance of organisms that are shelled marine organisms within a geologically rapid time, relatively speaking, 10 to 30 million years as the smallest possible increment, which seems like a long time to us as humans. If my testimony goes very long, I think it's going to seem like several million years, but --
THE COURT: You're doing fine so far.
THE WITNESS: You know, time to paleontologists means something quite different than it means to ecologists and normal people. But these organisms appear over 500 million years ago. And we find records mainly of these shelled sea creatures, marine invertebrates we call them, snails and clams and their relatives back in that time.
Before this the record is a bit more difficult. It preserves different kinds of fossils that are a little bit harder to suss out. And this has been a really interesting area of study for paleontologists, biologists, geochemists, geophysicists for many, many years.
The way that Pandas treats this is to say that organisms appear with these adaptational packages intact at the Cambrian boundary, multicellular life first flowers here. No evidence whatsoever of fossil ancestors.
Q. Now, I'm sorry, is that a direct quote from Pandas?
A. This is a direct quote from Pandas, Page 71 and 72. They go on to infer directly that only an intelligent designer could do this. They state, on Page 94 and 95, that the great majority of these animal phyla, by which is meant sort of these major groups of invertebrates, the arthropods and the annelids and the echinoderms and the mollusks and so forth, brachiopods, appear in a remarkably brief period of time, again, 10 to 30 million years.
We'll have recourse to that 10 to 30 figure in a second. But they say they're not connected by evolutionary intermediates, and there's an unexpected lack of fossils bridging the evolutionary distance between these phyla to document evolutionary origins for them.
Q. What does that mean?
A. I'm not sure. There are some code words there. I would agree that the fossil record is not complete. It will never be complete. On the other hand, how many intermediates do you need to suggest relationships, and what do you accept as intermediate?
And in the previous paragraph, there is some text that's even more worrisome because they say that these are adaptational packages that appear at the Cambrian boundary, by which they mean the boundary between the pre-Cambrian and the Cambrian. They say that multicellular life first flowers there, whatever that means, but they say there's no evidence whatsoever of fossil ancestors.
Q. And is that true?
A. Well, I think the record will show us something different. Before we go to the next slide, however, I want to point out at the bottom that after talking about phyla, groups of phyla, these major divisions of animals that are apparently having no bridges between them and no ancestors, they then go on to say that categories of classification are largely artificial human groupings.
I would agree with that, but it contradicts what they say in the previous passages, because if you treat phyla as somehow real entities that you cannot bridge, then how can you also say that these categories are largely artificial?
The next slide shows a bit of this pedigree, again from scientific creationism. A quote here from Henry Morris, who is head of the Institute for Scientific Creationism outside San Diego, from his textbook of more than three decades ago claiming that all of these kingdoms, phyla and classes unchanged since life began, that things appear suddenly, no incipient forms leading up to them. There may have been changes within kinds, but they haven't varied since the beginning except for those that have become extinct.
Q. And that's what Henry Morris said?
A. That's what Henry Morris said as a scientific creationist. This language is, I think, identical to what you see in Pandas. And, again, the statement from Pandas that I just read is below that.
Q. And that's from Page 71 and 72 of Pandas?
A. Yes.
Q. And is that accurate?
A. Is it an accurate representation of science?
Q. Yes.
A. I believe it's a little more complex than that. The next slide is another quotation from Duane Gish, who we've seen before as the vice president for the Institute for Creation Research. Duane Gish is talking about the Cambrian geological strata, a sudden great outburst of fossils, and he says that what is found in rocks supposedly older than the Cambrian, that is, in the so-called pre-Cambrian rocks, he says not a single indisputable fossil, unquote. This is very reminiscent of the language we've just seen in Pandas where they say there aren't any ancestors.
And if I could show the next slide. This quotation, also from Pandas, implies quite directly that there are no chains of fossils leading from lower organisms to higher ones. They stress that we can only accept evolution if we assume that only natural causes were at work to explain these things.
But then they say there's another possibility that science leaves open to us, and that is that an intelligent cause made fully formed and functional creatures which later left their traces in the rocks. This is as close a definition as I could come to special creation. I don't see how else you could interpret that as the possibility that natural processes could have gotten you from one form to another.
Q. And you are just quoting from Pages 25 and 26 of Pandas?
A. This is Pages 25-26 of Pandas.
Q. And what is this slide, Professor Padian?
A. This diagram comes from Page 95 of the second edition of Pandas. It's Figure 4.2. I can best describe it by the caption provided, their own caption, which says, This is a generalized schematic of the fossil record that's designed to show the Cambrian origins of nearly all animal phyla. Dotted lines represent the presumed existence of phyla, not the fossil record.
Again, I'm not sure what this chart is meant to represent, because what students are not being shown here or, indeed, any readers, there's no real time scale on here, so the implication clearly is that the vast majority of these things appeared all at once at the Cambrian/pre-Cambrian boundary. Boom, there they are. And if you look at that line below the Cambrian, where it says pre-Cambrian, there is no record whatsoever. There are no fossils as far as they're concerned.
They say in the caption this is a generalized schematic of the fossil record. They don't tell you which animal groups they're talking about, and they don't give you any idea that there could be any possible relationships among these organisms.
And so the question of whether that's an accurate depiction of the fossil record may be illustrated by this diagram from Kevin Peterson and his colleagues in Paleobiology earlier this year.
Q. I'm sorry, what is that text?
A. Paleobiology is a peer-review journal in our field.
Q. And that's 2005?
A. 2005. What the authors have done here is essentially to turn the rock column on its side, so time is now going from the lower left to the lower right as we move up into the Cambrian early and late. And you can see the boundary here between the Cambrian and the Ediacaran period right before that.
Q. Professor Padian, you have a pointer, a laser pointer there. It might be helpful to show that.
A. Okay. We'll see if it works. I can see that there. Okay, I can kind of see it myself. I'm not sure if that's visible to you.
THE COURT: We can see it.
THE WITNESS: Okay. The dark bars here, the dark black bars, are the actual fossil records of organisms. The gray bars you see here, these are cases where there are fossils that are supposed to be this old, but they haven't been verified yet.
The lighter colored black bars here are inferred existences that are inferred by a different line of evidence. These red boxes with numbers in them are dates by which scientists estimate when the divergences between -- that is, the separations between lines like this took place, the annelids and the mollusks.
You may ask, how is this done? And the answer is, well, molecular biology looks at the configurations of genes on chromosomes. By lining up the genes, the sequences of the genes are homologized and matched up with each other, and the closest matches and the more derived similarities, the unusual features of evolution, tell us which groups are most related to which.
Now, in the Pandas diagram, all of the names on the right-hand side in these various colors, the names of the major groups of organisms were not given, and there was no indication that we had any idea that these lines could be related to each other.
But, in fact, we had morphological ideas based on fossils, on embryology, and on the shells and tissues of these animals. Molecular biology has now come through with a whole other wealth of data. And this is --
Q. I'm sorry, in the red boxes, those are dates?
A. The red boxes are numbers that are estimated dates of when each of the lines in question would have separated from each other based on how much their molecules differ or resemble each other.
Q. So that would be the age of the fossils?
A. That would be the age of the splits of the lineages. The fossils may not extend back that far. Sometimes they get nearly that far, and sometimes they don't.
The fossils are represented by the little purple boxes below the slide here. There you see the purple boxes at the bottom. And, for example, here at about 600, we have listed the oldest metazoans. Metazoans are multicellular animals with several distinct tissue layers, so they would include actually all the animals here on this slide except the bottom two, and the bottom two, as their names suggest, are sponges.
And it turns out that the molecular date shows a divergence time at about 604 years. The oldest metazoans are dated, estimated in the fossil record at this date, as well.
Q. I'm sorry, you said 604 years. That's 604 million years?
A. Million years, yeah. The next slide I think will give an indication of not so much the relationships of these organisms, but of the fact that, indeed, before the so-called Cambrian explosion, there was a lot of evolution.
For example, the Cambrian explosion listed here in yellow -- and I'm not sure if I can make this -- yeah. The Cambrian explosion here of skeletonized animals is seen by scientists as really mostly a preservational artifact, although a lot of evolution is going on. But this is the point in history in which a lot of skeletons begin to be preserved, where before this we're not getting that much.
So the Cambrian explosion here is occurring along this yellow bar from about the Cambrian boundary well up into over 520 million years ago. It's not a single abrupt process but rather it's a process that takes quite a long time.
Even after this so-called Cambrian explosion, there are amazing preservations of fossils, soft-bodied critters that show us remains that we don't find earlier just because they're not preserved. It's very difficult to preserve fossils.
And at this Cambrian boundary where, according to works like Pandas, there are no fossils before that, there are no transitions, there are no possible ancestors, well, one of the things I pointed out before is that, you know, we're not always looking for direct ancestors, we're finding things that have the same features as the organisms that we're trying to understand the relationships of.
And so this pre-Cambrian record is actually quite interesting. We have fossilized animal burrows, and the burrows of these animals go in sort of all sorts of curvy lines and wavy lines that indicate that the animals were proceeding front to back, so they were what we call bilaterian, that is, two-sided things like us, like snails, like worms, like things that are -- have a left and a right side. This is the way they walk.
So even though we didn't have their shells or other remains of them, we have their burrows that could only have been made by complex metazoans that were also bilaterians, that is, two-sided animals. We can even go back --
Q. I'm sorry, and those have been dated before the Cambrian boundary?
A. Oh, yes. Everything that you see at the Cambrian boundary is over 540 million years old, and these are things that are still older than that.
Q. And on the right-hand side of this slide, there are several photographs. Can you tell us what those are?
A. These are photographs of the actual fossils. This is the actual fossil evidence that is preserved. These are taken from, in some cases, peer-reviewed books and journals and in some cases Web sites where the specimens are well known from other sources.
I want to point out that at about 590 million years there's a little dot there where it says "fossil metazoan embryos" at the bottom of the slide, and there's a picture of one of them.
This is a really amazing find because it shows us that some 50 million years before the Cambrian boundary and even longer before some of the Cambrian explosion took place, we have evidence of metazoan embryos. By that we mean the embryos of organisms that belong to one of the groups I showed in the previous slide.
How do we know this? We know this because the embryos themselves have characteristics of metazoans. They are not simply one-celled organisms. And if there are these embryos then, then there are metazoans present. That doesn't mean that there are full-blown trilobites and snails and brachiopods and so forth, but it does mean that there was some kind of metazoan life.
Q. And is this well established in science?
A. Oh, yes. It's the subject of countless articles and books and papers. And a few of them just are here, along with a recent book by Jim Valentine, who is emeritus professor in my department, member of the National Academy of Science, and one of the four or five most important paleobiologists of the last century, and he treated this problem and all its ramifications in depth.
Q. And if you could just read the titles and the journals from which they came into the record.
A. The top one is, Fossils, Molecules, and Embryos: New Perspectives on the Cambrian Explosion. This comes from a journal called Development.
Now, Development is about developmental biology. Would you expect to see fossils in developmental biology? Well, as I said before, this is the new age of integrative biology. Fossils are really important to all kinds of evolutionary study. They're incredibly indispensable to this sort of work.
A paper below that from Integrative and Comparative Biology, which is, again, not a paleontological journal, by Nick Butterfield called, Exceptional Fossil Preservation and the Cambrian Explosion, because we see this as a problem of preservation, not just of quick evolution. Both things are going on here.
And, finally, below in a journal called Molecular Phylogenetics and Evolution, again, not a journal you'd think the average rock hound would be publishing in, but we have Current Advances in the Phylogenetic Reconstruction of Metazoan Evolution, a New Paradigm for the Cambrian Explosion?
And these are all journals and articles that show the integration of molecular techniques with the fossil record, with developmental biology, and this is why it's one of the most exciting areas you'll find.
Q. And so the statements you've read to us a few minutes ago about the way Pandas characterizes the Cambrian boundary and says that there are no fossil ancestors before that boundary, that's not supported by the state of science today?
A. Well, as we can see, there are some metazoans that appear well before the Cambrian boundary. If you are looking for direct ancestors, if you insist on an unbroken stream of intermediate fossils to document a case, I'm afraid that that's going to be difficult to get under any circumstances, but it's also equally impossible for the historical record of humans.
If we had to come up with evidence of every one of our direct linear or collateral ancestors and know everything about them, it would be impossible, yet we don't question the parentage of our friends and neighbors because they can't do that.
Q. Now, we talked about the evolution of invertebrates. Can you talk to us about how Pandas portrays the evolution of vertebrates?
A. Yes, I would like to talk a bit about some of the major transitions that are discussed in Pandas that relate to backboned animals, which are closer to home, as far as we're concerned, because we belong among the backboned vertebrates. The text from Pandas says that fossil types are --
Q. I'm sorry, are you quoting?
A. I'm quoting from Page 22. Fossil types are fully formed and functional when they first appear in the fossil record. For example, we don't find creatures that are partly fish and partly something else leading to today's fish.
They say, Instead, fish have all the characteristics of today's fish from the earliest known fish fossils, reptiles in the record have all the characteristics of present-day reptiles, and so on. This is, again, the abrupt appearance theory, sudden appearance complex adaptive packages, irreducible complexity argument.
Q. So this says fish were formed intact?
A. Yeah, pretty much, yep. Here is their treatment of amphibians.
Q. And this is a slide from Page 104 of Pandas?
A. Page 104, yes. They say at the upper left column, Darwinists believe that the first amphibians evolved from early fish. "Darwinists believe," that's problematic language. It suggests to students that these are just matters of faith without any evidence. And for myself, I'd prefer to reserve matters of belief and faith for things that are not tested empirically.
The Pandas authors say in the next paragraph that if Crossopterygians, by which they mean the fish-like things, really did evolve into amphibians, by which they mean the first animals that came on land, tremendous changes must have taken place. Fins must have been transformed into four limbs, the skull had to change from two parts to a single solid piece. The hipbones had to enlarge and become attached to the backbone. Numerous changes must also have occurred in other soft tissues and so on.
They say in the next paragraph, How many different transitional species were required to bridge the gap? Hundreds even thousands? We don't know, but we do know that no such transitional species have been recovered.
Q. The next slide, is this a diagram from Pandas?
A. This is a diagram from Pandas of two forms from the fossil record. Eusthenopteron, which they take to be a fish, and Icthyostega, which they take to be an amphibian. Eusthenopteron doesn't look much like any fish you know. Neither does Icthyostega look much like any living amphibian. But in naming them like this, the editors, authors of Pandas are really giving them assignments to different whole groups of organisms and suggesting that the transition between them would be very difficult to achieve.
Certainly there are differences between these two skeletons. There are differences in the way they're drawn, as well as many features of their specimens that we find in the fossil record. And the next slide --
Q. I'm sorry, and that was from Page 103 of Pandas?
A. Yes. We've prepared some slides that show a bit more accurately the way that scientists understand this fossil record. What we've done here is to take the text from Pandas on Pages 103 and 104, but to illustrate our illustration of some of the major fossil animals that are known that move from aquatic, fish-like critters, up into the first animals that appear on land.
We're including in this Eusthenopteron, which is the second guy from the bottom left, and Icthyostega, which is three more guys up to the right from him, which are the two animals you saw in the last slide in Pandas. Pandas is giving you two animals and inviting you to draw contrasts between them. What we'd like to do is show the evidence that scientists have to show comparisons and to show the transitional features that the Pandas authors say do not exist.
So, for example, the text in the upper left taken again from Pandas insists in blue that no transitional species have been recovered.
Q. Could you read that please, that quote?
A. It says, How many different transitional species were required to bridge this gap? We don't know, but we do know that no such transitional species have been recovered.
Now, here, of course, we're going to focus on what are you defining as a transitional species? Does it have to be a direct ancestor, does it have to be intermediate in all features? Do you have to know that it had the same genetic antecedent composition and therefore could only have been the great, great, great, great, great, great grandfather of the next animal along the way?
That seems like a very difficult standard of evidence to live up to. We can't do that with humans most of the time, and I'd be surprised if we could do it with animals that are 350, 400 million years old.
The next slide looks a lot like the one you just saw. The Pandas authors say in blue that there are two large gaps in the fossil record that we're talking about here. One is between ordinary fish and Crossopterygians, what they would regard as the organisms that are closest to the land animals, and an even larger second gap between these lobed-finned fish and amphibians, again, the transition to life on land.
This slide just points out where the ray-finned fish are on the left. Ray-finned fish include the 25,000-odd species of fish that live today that we would all think of as fish, that is, tunas, trout, salmon, monkfish, angler fish, catfish. It would not include sharks, for example, which are cartilaginous animals. And it doesn't include any of the animals you see running along the right side of this slide. No one thinks that an animal like a trout directly gave rise to an animal like a frog.
Q. When you say "no one," no one in science?
A. No one in science, but I don't think any creationist obviously wouldn't think so, either. But scientists don't think this. Rather, we find that ray-finned fishes, this great radiation of 25,000 species today reaching back into the remote past, have a long history that's independent from the other watery creatures, so to speak. And, in fact, their histories are quite separate.
The two little crosses below the ray-finned fish and the two little crosses to the left of the lungfish are representations of two pairs of fossil species are that listed on the right-hand side. We call them stem taxa because they are ancient relatives. Their names here, just for a couple of examples, Moythomasia and Howqualepis. The names are really unimportant. And on the other side, Psarolepis and Achoania. Again, the names are unimportant.
But it just goes to show you that we have extinct relatives outside the lungfish. We have extinct relatives outside the ray-finned fishes that indicate that the ray-fins are not directly ancestral to the lungfish and all the other animals on the right side. They are rather a separate evolutionary branch, and they have been since way back in the Devonian, 400 or so million years ago.
The next slide talks a bit about another transition here where the Pandas authors note that fins must have transformed into four limbs, which is certainly fair enough, but they say that no such transitional species have been recovered.
Well, again, here is this cladogram that you see here. And I want to stress, as I did before, that the cladogram in question, that is, the way that we have -- the way that we have developed the relationships of the lungfish, the Eusthenopteron, Panderichthys, and all the other animals on this slide are not just based on a couple of features, they're based on dozens and dozens and dozens of skeletal characters of which we're only going to show a few. But this is backed up by a lot more evidence in peer-reviewed publications that I'll show you at the end of this.
The Pandas authors say that no such transitional species have been recovered, but, in fact, we have indications here, beginning with Eusthenopteron, of a limb that is a very interesting limb with branching bones in it.
Q. I'm sorry, the photograph just below the blue text on Pandas there, what is that?
A. That's a photograph of a limb of Eusthenopteron. And you'll have to excuse me, I'm showing you some Paleozoic road-kill. That's the best way I can describe it. It's pretty ugly. But I wanted to show you the actual fossils so you could see that we have them and then to show you next to that a drawing of what these bones actually are.
This doesn't look much like an arm of any animal today, but scientists have been able to compare the elements, which we've put here in the same colors, by the process of homology, which I'll talk to you about later. And there really is no dispute about the fact that these are, in fact, the precursors of limbs that we see in animals today, the same kinds of structures, the humerus here in yellow, the radius, and ulna, which are, I guess, in green, and then some of the features that become parts of the hand and the other digits in a darker color there.
You can also see that in the course of evolution, animals that begin having eight digits, such as Acanthostega here, reduce to seven digits, to six digits, and to five digits. I don't know how we could find anything more in the way of transitional forms or features unless we went to six and three-quarters or five and a half digits. But, I mean, that may be as good as we'll get in the fossil record in terms of a transition.
So we do have a very clear change, not just in the reductions of digits, but you'll also notice that they look a lot more digital-like the closer you get to the animals that we recognize as living amphibians and so forth.
In contrast, above, when Pandas teaches this to students, it gives them two animals and invites them to draw contrasts. It essentially does not identify any of the bones, does not indicate that you could have any identification between those two bones, places them in different positions, reconstructs an outline for them that may not be unreasonable, but it's certainly in a different orientation.
And its function, the cumulative effect is really to sort of confuse students, and certainly I'm confused looking at it about what I'm supposed to take out of a diagram like this, except the fact that, boy, these are different, and I don't see how we could get from one way to the other. It would have been so much nicer if they had used a diagram like the one at the bottom or acknowledged that we did at least have some transitional features that we could discuss.
Q. And that's Figure 4.9 from Pandas at the top of the slide?
A. That is Figure 4.9. The next slide is another feature. The Pandas authors, as noted before, said the skull had to change from two parts to a single solid piece, but, again, no such transitional species have been recovered.
Q. And, I'm sorry, that's what Pandas authors say?
A. That's what Pandas says, yeah. But as you can see, on this slide we can go easily from two mobile parts to two immobile parts to two parts that are fused and lack a ventral gap, that is, a one-part skull, to all the remaining vertebrates which have a one-part skull. This is a perfectly reasonable transition, morphologically and physically, and it's difficult to see how you could become any more transitional than this.
Q. So these are transitional fossil forms that have --
A. These are drawings of actual specimens and reconstructions of them from the scientific literature.
The next slide I think will indicate that although the Pandas authors say that the hipbones had to enlarge and become attached to the backbone, no such transitional species have been recovered, according to the Pandas authors.
But we can see, moving from Eusthenopteron up through Acanthostega and Icthyostega, that, in fact, you can go from small, unattached hind limbs and hipbones to become somewhat larger as you can see in Acanthostega and attached to the backbone by what we call a sacral rib. Our sacroiliac is the human equivalent of that.
And as you can see in Icthyostega and other animals, it gets even larger, expanded and attached to the backbone as these animals begin to use their limbs more in support of the skeleton. And as they come out on land, this will be even more important, as it is, of course, in the living animals which -- almost all of which have at least two sacral ribs attaching to their backbones.
So I think the next slide is just a depiction of some of the references from the scientific peer-reviewed literature from which the slides I've just shown you have given us the information.
Q. Could you just maybe read a couple of the titles into the record, please?
A. Yes. Fins to Limbs, What the Fossils Say, that appeared in Evolution & Development. Again, you can see where paleontology and developmental biology are seeing a great cooperation and a great number of new insights. From Fins to Fingers, again, a paper published in Science by Jenny Clack, who is a paleontologist at Cambridge. Fish-Like Gills and Breathing in the Earliest Known Tetrapod. So we can actually find fossil evidence even of some soft tissues which tell us a bit about these sorts of things. And I'd like to point out that these works are published in Nature, in Science, in the Bulletin of the British Museum of Natural History, and in the Philosophical Transactions of the Royal Society of London, among other publications.
Q. Dr. Padian, I note that some of these articles appear to be pretty old, for instance, Fins to Limbs appears to have been published in 1969, Bulletin of the British Museum is 1984. These were published before Pandas was written.
A. Yes.
Q. So the fact that there were, in fact, transitional fossils is something that was known to scientists at the time Pandas was being written and was published?
A. Yes. There were many fossils that had transitional features that were available in the scientific literature, as scientists understood them. And so for whatever reason, these were not included by the authors of Pandas. Perhaps they didn't accept it as evidence.
Q. And do you know why in Pandas they would misrepresent, it seems, or not accurately portray the state of scientific knowledge at the time?
A. Well, the Pandas book, as noted, promotes the view of intelligent design, which they state here 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, et cetera. I believe this is from maybe Page 99.
Q. That's right. And what you've just shown us is an evolutionary pathway?
A. Well, this is sort of worrisome, because scientists would interpret this as an evolutionary pathway, and intelligent design seems to be excluding the possibility that you can actually get those pathways. Now, we should note that as you pointed out, some of those publications I just showed were available when Pandas was written and some of them appeared afterward.
But it worries me that students would be told that they have to make a conclusion in advance of all the evidence that you can't get from A to B, essentially, by natural means. This quotation from Pandas says, Should we close our minds to the possibility that the various types of plants and animals were intelligently designed? This alternative suggests that a reasonable natural cause explanation for origins may never be found and that intelligent design best fits the data.
And so the question I would have is, what is a kid supposed to think when you tell him that you can't get from Point A to Point B and then evidence is uncovered that shows that, well, in fact, it looks pretty conceivable you can get from Point A to Point B and we're not making up this stuff.
Is a student supposed to say, well, gee, I guess there's no designer? Or is the student supposed to say, well, I guess the methods of intelligent design are really not very good? Or is he supposed to conclude something else? The intelligent design proponents provide no guidance on this.
Q. So when Pandas asserts that fish must have been created abruptly intact with fins and scales, really science has refuted that proposition?
A. Yes.
Q. And in the passage which I think virtually every expert witness has focused on in this trial, Page 99 to 100, when they talk about fish being formed abruptly and the other animal that's mentioned there is birds with wings, feathers, and beaks already intact, can you talk to us about whether or not there is an evolutionary pathway, natural explanation for the evolution of birds?
A. Well, I'd be delighted to, if I can look at the next slide. As it turns out, when I went to graduate school, my advisor there, John Ostrom, is the person who actually established the origin of birds from carnivorous dinosaurs. And this became very well accepted over the next several years. We are now 30 years on into that, and it is one of the great achievements of 20th Century paleontology and that kind of science.
And I did work on this myself in the course of 30 years of research, the origin of birds and the origin of flight and of feathers. And so I'd like to show a little bit about what science has understood about this.
The next slide, I believe, gives you two quotes from Pandas, along with a picture of Archaeopteryx, which is the first known bird. It's about 150 million years old. It comes from Germany. It's a beautiful fossil. This is the Berlin specimen. It's known from a number of specimens, seven or eight now.
And as you can see, it's got beautiful wings, feathers, look very modern in their appearance, and yet Archaeopteryx has a long bony tail, its skull still has teeth, it's got various configurations of bones that we don't find in birds today. Many of the bones of its hand and foot are not fused like the bones of living birds. And so it's been known since its discovery in the 1860s, the time of the Civil War, right after Darwin published the Origin of Species, that scientists have accepted this as an animal that shows a lot of intermediate characteristics between birds and other animals, particularly certain kinds of reptiles.
Q. And what does Pandas say about this?
A. Well, Pandas says that there is no gradual series of fossils that lead from fish to amphibians or from reptiles to birds, rather these animals are fully formed.
Q. And you were quoting from Page 106 of Pandas?
A. 106, yeah. And that's one problem that they come up with. And a second problem that they talk about on Page 22 is that -- is their bemoaning the lack of fossils that show scales developing the property of feathers. They say, then we would have more to go on, but the fossil record gives no evidence for such changes.
I've picked out these two quotes because I want to emphasize that in the first case, there was very good evidence for the evolution of birds from dinosaurs when they wrote Pandas. And in the second case, they were right at the time, we did not have very many fossils that showed anything about the origin of feathers.
But in the past decade, we've had a bunch of remarkable fossils that have. And so this raises the question again of, if you tell children that you can't get there from here and then evidence is found, what are you going to do?
The next slide, I believe, talks about some of the -- this is really just a montage of a few, I mean, it's just a very few of the papers about feathered dinosaurs, dinosaurs that are not birds, they didn't fly, but they had various kinds of very rudimentary feathers.
And these have been discovered in a remarkable deposit in Northeastern China, the first one in 1996, so this was after Pandas was written. And so we wouldn't expect those authors to know anything about these discoveries, but it just goes to show that there are some really interesting things that crop up.
Q. And could you just read into the record the titles of some of these?
A. An Exceptionally Well-Preserved Theropod Dinosaur from the Yixian Formation of China. This is a dinosaur with feathers. The next one is Two Feathered Dinosaurs from Northeastern China. Another one here is Branched Integumental Structures in Sinornithosaurus and the Origin of Feathers.
Q. In what type of journals were these published in?
A. These happen to be taken all from the journal Nature, which is one of those two magazines that I noted that all scientists are going to read every week. They're the most prestigious journals to publish in.
Q. And what you're going to show us now about the evolution of feathers is taken based on these peer-reviewed --
A. These and many others, yes. In the next series of slides, if I may, I'd like to show you three things going on at once, because I want to tell you that this is not simply a matter of speculation or of isolated observation and inference, that this comes from independent lines of evidence, not just the fossil record.
What I've done in this series of slides is to take, on the left, one of those hat rack cladograms that show you the relationships of organisms, and again I've turned it on its side. So you can see that Archaeopteryx and modern birds are on the bottom, and that successively the groups above them are various dinosaur groups that are closely related to them.
I want to stress that this scheme of relationships, again, is based on dozens and dozens of characteristics that are not controversial to any extent in the scientific community, and whereas we do have uncertainties about some of the minor relationships among these animals, this is the scheme that is generally accepted by paleontologists.
On the upper right, I want to show you a series of pictures that were taken from an article in Scientific American that reflects the work of Rick Prum at Yale and Alan Brush and Scott Williamson and their coauthors on the development of feathers, that is, how feathers develop in living birds.
And the reason for doing this is to couple this with a series of slides I'm going to show you on the bottom, which are of fossils of feathered dinosaurs, that is, dinosaurs that are not birds but that have feathers or some structures that are rudimentary feathers.
And what I want to show you is that as we proceed on the left up the tree leading to birds, we will also see that the feathers that are found in these little carnivorous dinosaurs in the lower right are becoming more and more complex and that they are reflecting the complexification of feather structure seen in the series of diagrams in the upper right as feathers develop embryologically.
So we're actually looking at phylogeny or relationships on the left, we're looking at fossils on the right, and we're looking at developmental structures and embryology on the upper left -- upper right, I mean. Fair enough? Okay.
Then in this stage, we see a little animal in the lower right, and that black fuzz that seems to be going along its backbone is recognized as the most basal traces of things that are going to become feathers. And these structures are hair-like. They look like the structures in the upper right. There has been observation suggesting that they are even hollow in their structure. And we find these at that point in the cladogram noted at Stage 1 on the left-hand side.
The next slide should show us Stage 2. Now we've just jumped up a notch in the cladogram. And here we're beginning to find not just these single filamentous features, but also feathers that begin to branch and begin to have different kinds of tufts involved with them. The specimen on the lower right I realize is a road-kill and it's difficult to interpret, but let me see if I can just give you a sense of -- there we go. Down here we have bones of the backbone, tail. And these black and white marks up in here are remnants of these branched, feathery structures that appear in these dinosaurs.
The next slide shows a further complexification of feathers in the next step up on the cladogram toward birds in which we have a gaggle of feathers there in the center. These are just a group of feathers that have, as you might be able to see, a central sort of stalk where you can see all these things gather in the middle. You can see this happening in the early development of a feather in the upper right. And then you see the feather differentiating into veins along a central stalk, just like you see in the next stage of the development of a feather in a bird that lives today.
The next slide, again, at this stage we also see another kind of feather that is a feather that is organized very well into veins on each side. And these veins are very well organized along the central stalk. In this fossil I've shown you in the middle, you can see perhaps faintly the outline of these black and white structures radiating off along this white stripe, which is the central axis of the feathers.
And so these are several feathers from the tail of one of these animals that are just bunched up right next to each other in one of these fossils. And, again, this is mirrored also in the progress of development from the feather from a single follicle bud up to a complete feather that we'd see today.
The final stages I want to show you as we get closer to birds is a feather in which the veins are asymmetrical, that is, one side of the feather is bigger and the other side is smaller. And this is seen in birds today, but it's also seen in some of the other carnivorous dinosaurs that are close to birds, but not in all of them.
So, again, what we're seeing is as we move up the cladogram towards birds, we go from the simplest filamentous feathers up to more complex structures that are then gathered and around a central stalk that produce veins. These are interlocked by barbs and barbules, and they eventually become the aerodynamic structures that birds use in their wings.
But I'd like to point out, if I can, in the next slide that the obvious question is, what are they doing with these feathers before they're flying? And the evidence that we found in the fossil record in the last ten years indicates beyond any reasonable question that feathers did not evolve for flight. Flight was an afterthought for birds. They somehow acquired that adaptation later on.
What do we know about those first little hairy feathers that we're looking at? Well, one thing we know is, if you put a fur coat on somebody, they're going to stay warmer. And this little covering of dense fibers is going to give you insulation. That tells us something about the metabolic status of these animals even then.
Another thing is, you may have noticed some dark and light color patterns on those feathers. The fossils preserve this. What good are color patterns? Well, on these animals, they could serve as camouflage, as display, or even to help them recognize species.
I'm going to show you another function in a second that indicates that these animals were also using the feathers to shelter the eggs as they brooded their young. And these are all examples of what we call exaptation and evolution. And by that I mean that a structure evolves for one purpose, but it's selected, in turn, to acquire a second purpose, without, of course, losing the first one instantly. It will retain the first one.
And as it develops the second one, because it has the ecological opportunity or the pressure to do so, that second structure, that second function, may become more and more important to the structure, it may be selected to change more to accommodate this new function. And this is how exaptation works to change one kind of function into another through evolution.
Q. You have at the top there, What good is a half wing? What do you mean by that?
A. Well, if you just -- this is the question that has always been asked of evolutionists. St. George Mivart asked this of Darwin in the 1870s, what good is half a wing?
And the answer is, well, if you don't think of it as something you have to use to fly with, you can find out other functions if you just let the evidence tell you. And these are some of the lines of evidence. I will briefly show, if I may, a couple of these other functions.
The next slide provides some additional evidence of the other problem we talked about, not so much feathers, but the question of the evolution of birds. We have tremendous evidence on this, but one line of evidence comes from the hand itself. If you look at the hand of crocodiles, they have got five fingers. If you go all the way over to the left, you see Archaeopteryx, the first bird, that has only three.
Well, again, here's a cladogram of relationship diagrams of how these organisms are related based on many, many characteristics. And as we move up from the crocodiles through the various kinds of dinosaurs, we see that the fourth and the fifth finger, first the fifth and then the fourth, become reduced and finally lost, until, when you get up to animals like Allosaurus, Deinonicus, and Archaeopteryx, they have only three fingers, and those are the first three fingers. The second finger is the longest, and you can see that through time, these fingers and the hand bones become even longer and more gracile.
Those three fingers that you see in Archaeopteryx at the end are still separate fingers, but in birds today, they're fused up. You would know them better as the pointy part of the wing in the Kentucky fried chicken.
So if you were to dissect your Kentucky fried chicken, which I don't recommend, but I can tell you about turkeys and Thanksgiving, which is a lot of fun, you will find that you can get to the individual hand bones, we can watch the bird develop, and these are individual bones that later become fused. And this is because the bird is no longer using its hand for anything except flight. It's not using its fingers to pick up things or claw or scratch anymore.
And early in the evolution of birds, when they dedicated themselves to flying with the four limbs and very little else, there was no further need to use these fingers for anything, and it made more sense to fuse them into position rather than use muscles to hold them there. And this is the evidence that we have of how these organs evolve.
The next slide, I believe, will give us one more thing about feathers and behavior, too. This is a dinosaur, an extraordinary ostrich dinosaur relative. It's an Oviraptor dinosaur. The name isn't important. But one thing you can see about this specimen, which is very beautiful, it comes from the Cretaceous of Mongolia, is that in the photograph at the top, I'm going to show you, here is the right arm, here is the humerus, the bones of the forearm, and three clawed fingers of the right hand. Moving over to the other side, the arm comes out here, and here are the three clawed fingers of the left hand.
These white objects you see in this specimen are eggs. And here is the hind limb and the foot on the left side. Here is the hind limb and foot of the right side. Here is part of the tail. And the animal's rib cage is in here. There are more eggs underneath this animal. This critter was brooding its eggs in exactly the same position that hens brood their eggs today.
Furthermore -- well, one thing to draw from this is that some behaviors that we associate with birds did not evolve with birds, they actually apparently were already present in the dinosaurian relatives of birds, and they simply were passed on to birds as they evolved.
But the other thing this shows is a funny thing. The fingers, you'll notice, are spread so as to cover the eggs. And in the fossil relatives of this particular dinosaur, not this specimen because they aren't preserved, but we have feathers in other Oviraptor dinosaurs that come off the fingers that are long and gracile. And if this particular dinosaur had preserved its feathers, it would have been using them to shelter the eggs as it brooded them. This is evidence of behavior, not just of structure, that we can find very anciently in the fossil record.
The next slide, I believe, shows an equally extraordinary find. And this is of a dinosaur, not a bird. He looks a lot like a bird, but he's in a sleeping position. And what is unusual about this critter is that here's its skull here with its big eye right here, and here's its little beak and its tail, bones like this. Up here are the arm bones of the left arm. And what this animal is doing -- his tail end is back this way and his front end is really to the left, but he's tucked his head and neck underneath his left arm. In other words, he's sleeping like a bird does. This is not a bird. This is a little carnivorous dinosaur that's close to birds.
So, again, there is remarkable evidence that not just the structures of birds, but the behaviors of birds can sometimes be found in the fossil record and they precede birds. They actually are more general. They apply to the fossil record of many dinosaurs, as well.
Q. And, again, this is all based on peer-reviewed research?
A. The paper you see there is from Nature.
Q. And so do scientists today understand that, in fact, birds evolved and were not created abruptly?
A. In fact, that they evolved from small carnivorous dinosaurs sometime in the middle or late Jurassic period about 150 million years ago.
MR. WALCZAK: You Honor, I know there have been a number of references to food here. I have one more very short topic that I'd like to cover with Professor Padian, and that will be a good place to break.
THE COURT: After that point?
MR. WALCZAK: Yes.
THE COURT: That's fine. I thought we'd go to about no later than 12:15, but if it takes longer than that, that's fine. Let's break at whatever point you think is logical so that we don't break up the testimony unnecessarily.
Q. Professor Padian, you talked about this change of function, and I think you used the term "exaptation."
A. Yes.
Q. Is that a biological concept that's well established?
A. Yes, it is.
Q. And how do intelligent design proponents deal with exaptation?
A. Well, as far as I can tell, they don't really. It's very difficult for them to deal with exaptation because it implies that you can take a structure and change its function to a new function. And the whole purpose of intelligent design is to identify structures and functions that are too complex to have changed naturally from an antecedent state to a new state.
I believe that the evidence that I'm providing here is trying to show that we have, piece by piece, assembly of major adaptations. I believe that we've shown that with the transition of swimming animals up into the animals that came onto land, for example, a very good transition of features step by step by step, and that it isn't like an adaptational package of land animals that had to be assembled abruptly, but rather that structures are changed in their function.
So, for example, the fin of a fish moves up and down and helps it to negotiate the water, that is, to push water, pass it or to steer and do things like that in a medium that's a thousand times denser than air.
How do you get from that to an animal that puts its limbs under its body and stands on this limb? Well, as we've seen, what happens in the evolution of limbs from basic fins is that these bones become stouter and stronger. Their articulations change. They begin to be able to be much more able to support weight, and they change from having a lot of those individual sort of rays that you see in any fish fin to a fewer number of things that are covered by flesh. In fact, these are the fleshy fins that we have, our hands. They're exactly the same structures.
And we saw from the slides that these structures, the numbers of fingers, how they articulate, change in a very step-like pattern, not in an abrupt way at all. So the answer is that intelligent design proponents, this is the last thing they want to hear, because it would indicate to them that there are ways of getting from Point A to Point B when they want to talk about abrupt appearance and irreducible complexity.
MR. WALCZAK: I'd like to end abruptly now so we could get some lunch.
THE COURT: I don't know if there will be a run on chicken. But we'll break here until -- how are you proceeding time-wise?
We could take an abbreviated lunch, take an hour rather than the longer lunch, or we can go to 1:30, which might be a little bit more reasonable. I'll give you a crack at that because you know how much more you have on direct and you want to save time -- I know you don't want to bring this witness back -- you want to save time, reserve time for appropriate cross.
MR. WALCZAK: I'm guessing an hour, maybe a little bit more. We've got mammals, we've got whales.
THE COURT: Mr. Muise, if we stopped at 2:30 or if we gave Mr. Walczak until 2:30, if we reconvened at 1:30, would that give you enough time to cross-examine?
MR. MUISE: 2:30 and stop at 4:00, Your Honor?
THE COURT: Well, no, we'd stop at 4:30-ish. That would give you two full hours. But if you don't think that that's going to be enough, I want to try to regulate what we're doing here.
MR. MUISE: It's always hard to judge, Your Honor, you know, for cross-examination, depending on, you know, how the responses come, obviously.
THE COURT: Well, I'm saying I would hold Mr. Walczak, because I know there's an issue -- this witness has come a great distance. I would hold him to 2:30. You've got to keep it within two. Now, you may not use two, but I'm saying, is that enough? Now, if you want a little over, that's fine. I'm just trying to get a fix on --
MR. MUISE: Let's do an abbreviated lunch since we want to make sure we get done.
THE COURT: Let's take precisely an hour. We'll come back at 1:15. And then why don't you have a conversation during the lunch break about how you want to carve up the afternoon, because I think that's the appropriate thing to do.
So, Mr. Walczak, if you don't go too deeply into the afternoon and not give Mr. Muise enough time, in the interest of not bringing this witness back -- which I think is what you're striving to do. Am I correct?
MR. WALCZAK: That's right, Your Honor.
THE COURT: So as a courtesy, make sure he's got enough time. All right?
MR. WALCZAK: Yes, Your Honor.
THE COURT: We'll be in recess until 1:15.
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