A conversation with Kevin Padian
A paleontologist tackles scientific literacy and the battle over evolution, and claims dinosaurs still live among us. Published in California Monthly magazine.
There can’t be many biology professors who hated science in high school. But that’s exactly how Kevin Padian puts it, and with passion–”I hated it.” When he was growing up in a small New Jersey farming town, he didn’t even take high school biology; and by the time he entered his second semester at Colgate University in 1968 he was getting ready to “settle down to another D” in his required science course.
That was when his regard (or disregard) for science changed. Padian’s professor told the class, “If this isn’t really what you’re into, come down afterward and talk to me, and we’ll see what we can do.” Padian was “down there in a flash” and, after a brief chat about his interests, was soon reading The Immense Journey, a book on evolution by the naturalist-poet Loren Eiseley. The book, says Padian, was “seductive in its beautiful explanations of how life evolved,” and he went back for more. He eventually created his own major: natural sciences with a focus on evolution. He then decided he was going to teach science. “The reason I decided this was because I had always hated it,” says Padian matter-of-factly. “I couldn’t relate to how I had been taught, and I thought if I could just learn how to teach it, I might actually reach kids like me who wouldn’t otherwise be interested.”
He got his teaching credential from Colgate in 1973 and taught high school science for two years; he then decided he needed to go back to school himself because he felt he “didn’t really know enough science to be a good teacher.” He attended graduate school at Yale, where one of his advisers was John Ostrom, the paleontologist who first made a convincing case that birds are descended from dinosaurs. Padian wrote his dissertation on the origin of flight in pterosaurs, flying reptiles that lived at the time of the dinosaurs.
When he finished his Ph.D. in 1980, he says it dawned on him: “I know how to be a scientist now.” Instead of returning to teach high school, he was lured to the West Coast with an offer to join Berkeley’s Department of Paleontology (now part of Integrative Biology). His current research focuses on the evolution of flight in birds, but also covers dinosaur growth and metabolism–work, he says, that shows that dinosaurs were probably warm-blooded–as well as how those animals walked and ran. He is also a curator of the campus’s Museum of Paleontology, where Berkeley’s famous T. rex is housed.
For many years, Padian taught the lower-division course Age of Dinosaurs. He has just begun teaching a course covering “the history of evolution as a science and how it relates to philosophy and social issues, and then macroevolution, the grand sweep of evolution.” He often runs seminars on the history of evolutionary thought and is an occasional contributor to history of science journals, although he says he’s not comfortable calling himself an historian of science–”I’m a dilettante.”
He frequently reviews books on paleontology and the history of science for national and international journals and is a strong believer in the power of writing, which he calls “a great stimulus to thinking.” He has just finished a three-year tenure as director of the College Writing Program at Berkeley–”one of the really great programs on campus,” he says.
Padian remains involved in science education at the pre-college level. He was one of the main authors of California’s K-12 Science Framework (1990) and has served on a number of committees evaluating textbooks for the state. Despite his early difficulties with classroom science, Padian is now among its staunchest advocates, particularly in his role as president of the National Center for Science Education, a nonprofit whose aim, he says, is to “keep evolution in the science classroom and ‘intelligent design’ and other pseudoscience out.” He is a fellow of the California Academy of Sciences, a recent visiting professor at both the Collège de France and the Museum of Natural History in Paris, and the recipient of the 2003 Carl Sagan Prize for Science Popularization.
As the new school year began, we sat down with him in his office in the Valley Life Sciences Building to find out what everyone should know about science.
I grew up in the age of Sputnik. When the Russians got ahead of us, everyone started to think science had to be much more rigorous, much more oriented towards physics, chemistry, cell biology–”hard science.” And so, in seventh grade, we were learning about plasma and osmoregulation and other 25-cent words, but not why the sky is blue or how dinosaurs evolved or why we had an ice age. I never learned about the things that interested me, so it was just dull. It wasn’t aimed toward giving students a full appreciation of the natural world.
For me, like many students at Berkeley today, science was something I would have never taken a course in if I hadn’t had to. Then I met Bob Linsley, a paleontologist at Colgate who worked on Devonian snails. He was just great. He not only knew everything about his subject, he was also a kind person and a fabulous teacher. People would come from other universities to observe him so that they could become better teachers. It was his infectiousness, his enthusiasm for science.
Back then, everybody used to teach paleontology like it was the telephone book–you just learn all the snails, all the echinoderms, all the brachiopods. But Linsley said, “What’s the use of this? Sure, expose people to that, but give them the concepts they need so they’re able to go out and ask the questions.”
Is that your philosophy of teaching, too?
Absolutely. I don’t try to make explanations technical, I try to make them full. One thing I learned from teaching kids is that if you can’t explain it to a sixth-grader, it’s probably not a very clear idea. I’d prefer people leave my classes with stimulating ideas rather than crammed with too many facts. They can always get more facts later.
Berkeley has the best faculty in the country, the best graduate students in the country–it should have the best undergraduate training in the country. And you get that, I think, by teaching critical thinking. Students should learn how ideas were formed, how they fit with other ideas, what the controversies are, and what we still need to know. But, especially, it’s important to learn the standards of evidence and the methods, because science rests on these. In other words, people should be scientifically literate–in the voting booth, in the political arena, in the social arena. If people in the best universities in the state don’t teach that, who’s going to do it?
Doesn’t Berkeley do that?
Yes, we do. But there’s an interesting imbalance, for example, when all science majors have to take physics and chemistry, but not all have to take biology and geology–not to mention learning a bit about why the philosophy and history of science matter. This is the case in virtually all universities, not just Berkeley. But why shouldn’t all science majors receive a broad science education?
What about science education at the K-12 level?
Science should be taught for literacy there, too. There are certain central theories that are very important in science that people should know about. I don’t think they should necessarily know how to do intricate chemical equations–most people won’t ever have to calculate how many moles of sodium chloride you need to make x liters of some kind of molar solution. Yet people have no idea what’s in the food they eat. Why shouldn’t that be in a chemistry class? I’m not saying it all needs to be applied science or dumbed down; I mean that you have to take concepts and use them to make people literate about what they’re encountering in the world. But, in some respects, we’re still teaching for the Sputnik generation.
What are the central theories we should know in order to be scientifically literate?
When we were designing the science curriculum for California public schools, we took earth science, life science, and physical science, and we said there are three main theories that hold these sciences together. In earth sciences, it’s plate tectonics. In biology, it’s evolution, because nothing makes sense without it. And in the physical sciences, it’s energy, because energy is the basis of chemistry and physics, and people need to understand the different forms of energy and its transformations. All of these concepts are broken down into simpler building blocks for the K-3 level, the 3-6 level, the 6-9 level. Then you interweave them, make them more complex, and start to relate them to other fields.
One of those central theories–evolution–is your area of expertise, yet many people still oppose its teaching in public schools.
That’s true. It’s a little disconcerting. People are entitled to their beliefs, but to be educated they have to be open to learning about other ideas. We even have a lot of biology majors here at Berkeley who have been told not to accept evolution.
That seems extraordinary. Are they taught this in school?
Generally, students learn this in their churches. Of course, most religions don’t have a problem with evolution, and scientists of all sorts of religious persuasions see no conflict between evolution and their personal beliefs. But the face of Christianity has changed in the U.S. over the past 50 years or so. The proportion of conservative and fundamentalist sects has grown, and our students reflect this. Our business isn’t to change their belief systems, but to educate them about what science really does. The misconceptions that some students have been given about science are really appalling.
Opponents of evolution have been trying to change what’s taught in schools. Have they had much success?
Interestingly enough, they haven’t made much headway at the state and national levels, and this is because the courts have always sided with good science. But that doesn’t stop them; they simply try a different tack, intimidating teachers and principals at the local level, where their influence is less visible. A great deal of the work that our nonprofit [the National Center for Science Education] does is to advise teachers and principals and school board members about what the science is and what the legal decisions about the science have been. The difficulty is that when a subject is criticized in school, for whatever reason, it becomes “controversial,” and many teachers shy away from teaching it. So the effect is the same as getting it legislated out.
On the public side, for some decades there’s been a tremendous campaign of disinformation about evolution, which comes largely from various conservative Christian groups. These people basically misrepresent what science does and doesn’t do, and then they demonize that as a way of trying to get their theological position into American institutions as an alternative. This is exactly what the so-called “intelligent design” movement is all about. This is a sociopolitical movement begun by our own emeritus law professor Philip Johnson.
What is meant by intelligent design?
It’s the idea that evidence of a supernatural creator can be found in the intricate design of living things. It goes back to a middlebrow theological movement in late 18th-century England. The modern version of I.D. has three self-described aims: science research, changing American institutions, and public relations. They’ve done a lot of public relations, and they’ve done a lot to try to institutionalize their views–such as testifying in front of state boards of education to include bogus “evidence against evolution” in curricula. But they haven’t done any science. Proponents of intelligent design haven’t published a single peer-reviewed paper in the ten years since they announced their plan, but they’re already getting on the field and claiming they’ve won the game and that they should be in classrooms along with everybody else in science. Whether the universe is intelligently designed by a creator may or may not be true; but it’s not a scientific question, and it doesn’t belong in science classrooms.
Why do so many people find it difficult to reconcile evolution with their religious beliefs?
One thing that scares a lot of people is the notion of randomness. They fear that if the processes that shape the evolution are “random,” there’s no purpose or direction to life. Both those statements are wrong–first of all, because that’s not what “random” means in science and, second, because I think you can find purpose and direction in the evolution of life, just not a religious one.
This is really the fault of scientists for using common words in specialized ways and not explaining them very well to the public. We need to take the rap for this misunderstanding. Randomness in evolution, or in science in general, is just a statistical term. It means that we can’t individuate specific cases in advance. We may know that six out of a thousand fruitflies in every generation will have a particular mutation, but we can’t say which six. That’s what we mean when we say that this stuff is random. And mutations themselves are not random changes. They are changes in the genetic material–the genetic material does certain things but not other things. We know, for example, that a duck’s head is not going to suddenly appear on a horse. In fact, Darwin’s great idea was natural selection, which is the very opposite of randomness. Think of it this way: Were our students selected to get into Berkeley, or did they just get in at random?
You said there is a purpose and direction to evolution.
Well, I would say that there is an obvious direction to evolution. It’s called time. Time and inherited change give us evolution. There’s also a purpose to evolution, in a secular sense: life’s purpose is to sustain life, to procreate and survive. That “purpose” is manifest in the scientific evidence itself. It’s not a philosophical or religious idea. If you want that, you have to bring it in from elsewhere, and people do. It’s not science to do that, and that’s fine. Science is just one corner of human knowledge.
You’ve also been on panels evaluating science textbooks. What sort of problems do you find there?
Most writers of K-12 science texts, we found out, aren’t scientists; they don’t get the difference between inductive and deductive science and they don’t understand historical versus nonhistorical sciences. So when you open a textbook there will be the “Scientific Method” and it will be the five steps: state your hypothesis, gather your material, design your experiment, then state your results, and form your conclusions. Well, that leaves out the half of science that’s not subject to direct experimentation.
Including your own field of paleontology.
Right. We can’t reproduce the past or control its variables. Neither can geologists or astronomers. We can only “experiment” with the past by doing simulations and models. We’re dealing with natural phenomena that happened only once.
Paleontology is the most historical of sciences in many ways. We study the evolution of the earth as well as the evolution of life; the study of evolution in the large sense is to uncover the history of life–the “begats” of the Bible writ large. So we’re steeped in history all the time. My interest has always been in looking at a particular aspect of the history of life–how large-scale adaptations occur, how major groups evolve, how big changes get started in evolution.
You’re also interested in the history of evolution as an idea. What can we learn from Darwin and his contemporaries?
Patience. And humility. When you look at what those people figured out, knowing so much less than we know now–whether their answers agree with what we think today or whether they were gloriously wrong–it really makes you think how incredible it was that they were able to make any progress at all. It was so much more time-consuming and difficult to get information. And they thought about problems in such different terms than we do today.
You’ve written quite a bit about the work of the staunch anti-evolutionist Richard Owen. Why is he interesting?
Richard Owen is the only man Darwin is ever said to have hated. He was Professor Moriarty to Darwin’s Sherlock Holmes. His worldview was so different from Darwin’s thatThe Origin of Species is in some respects a response to Owen. Owen did accept evolution after a fashion–he could not avoid the conclusion that life had evolved through time–but he didn’t accept natural selection because he felt it was so purely mechanistic.
Owen was also the leading biologist of his day. He had his hand in everything–he tutored the royal children, he named the Dinosauria, he produced the first reasonable classification of the mammals. Even today, when you pick up a typical seventh-grade life-science textbook, you’ll find that they still teach fishes, amphibians, reptiles, and mammals as very separate groups of animals. They often say, for example, that animals are classified first by whether they’re warm-blooded or cold-blooded. Well, that’s Owen.
So children today are taught Owen’s way of classifying animals, not Darwin’s?
Exactly. It’s an old, pre-evolutionary classification system. We have these anciently known categories–amphibians, reptiles, and so on–but they’re pictured almost as fixed categories, not related by descent. Darwin’s idea of classification based on descent was very important. He said classification has to be driven by some sort of principle. And since we understand evolution to be descent with modification, classification should be based on that. In the old school, people would contest vigorously that birds should be included in dinosaurs and reptiles because birds are so different from typical reptiles. Well, yes, they’re different. But everybody comes from somewhere. The point is that birds and dinosaurs share evolutionary features.
Some scientists still contest the idea that birds are descended from dinosaurs.
Science doesn’t require unanimity. The fact that some people disagree is normal, but it’s not a scientific question. This “controversy” is accepted as settled by the scientific community because there have been dozens of phylogenetic analyses of this question [which use the principle of classification based on descent] and they all come to the same conclusion. In contrast, the opponents have no phylogenetic analyses on their side, so there’s nothing positive for other scientists to evaluate.
What is the evidence that birds are descended from dinosaurs?
In the early 1970s, John Ostrom, one of my advisers at Yale, figured out that there were a lot of detailed similarities between Archaeopteryx, the first known bird, and the small carnivorous dinosaurs he’d been studying, called theropods. In the intervening years, people kept finding more and more evidence of an evolutionary link, and every new discovery supported that idea, right down to the recent findings of feathered dinosaurs sitting on nests with eggs.
Jacques Gauthier, who was one of my grad students in the ‘80s, and I wrote a paper describing the action that these little carnivorous dinosaurs used for reaching out and grabbing. It’s a very unusual motion. They’re the only animals that can do this; they have a funny wrist joint that only these dinosaurs and birds have. We showed how it evolved and how that grabbing motion is kinematically equivalent to a flight stroke. To me, this business with the wrist and the hand is really important. It’s both the key to the adaptation of flight and another piece of evidence for their evolutionary relationship.
The discovery that birds came from dinosaurs is really one of the more important discoveries in biology in the 20th century. Moreover, birds are not just evolved from dinosaurs; by inclusion they are dinosaurs.
Why should we care where birds came from?
I think it’s great news that birds are dinosaurs. It means that dinosaurs aren’t technically extinct! Thousands of dinosaur species are still alive: we call them birds. Lowell Dingus and Tim Rowe, two of our former graduate students, wrote a book on bird evolution called The Mistaken Extinction. And it’s great news that we humans are also apes, that we’re primates, we’re mammals. It gives us a feeling of the unity of living things–which we now know share a common DNA and RNA structure, and so much more. Many scientists and others who study evolution, including very religious people, are very much sustained by the thought that there is a unity of living things. Darwin saw this completely. As he said in the last paragraph of The Origin of Species: “There is grandeur in this view of life.”