Dealing Fairly with Bones of Contention That complex human beings are the evolutionary descendants of primitive simple protozoa is not, as Johnson asserts, "naturalistic doctrine," but rather a reasonable scientific inference drawn from all that is known of the tree of life, the common chemistry of living things, and the well-confirmed general processes of evolutionary development. School biology and geology teachers are not teaching atheistic, materialist metaphysics when they discuss the evolutionary roots of the tree of life or the ancient depositional origin of sedimentary rock formations any more than English-language teachers are when they explain the Latin or Sanskrit roots of the words students are to learn. Indeed, many science teachers these days are barely even teaching the basics of evolutionary theory at all. While teaching at a university in Texas I asked students in my classes about what they learned about evolution in high school, and was always dismayed at the large number who did not even have a cursory exposure to it. My experience seems to be typical; in a survey of close to a thousand first-year college students who either had nonscience or undeclared majors, one professor found that more than twenty-five percent said they believed that God created the earth within the last 10,000 years and formed human beings exactly as described in the Bible (compared to forty-seven percent of the general population who had that view, according to a 1991 Gallup poll). Another fifty percent said they were undecided as to whether evolution is a valid scientific theory or a hoax. (Interestingly, students who attended Catholic high schools typically have had the best education in evolution, probably because the Church has long held evolution to be compatible with Christian faith.) Even teachers who want to give their students a good education in evolution often choose to avoid the topic in local districts where creationist activists have made it a contentious issue for fear of complaints from creationist parents. Eugenie Scott, director of the National Center for Science Education, writes that "in the face of parental pressure, principals and superintendents frequently fail to support teachers, even when the curriculum mandates the teaching of evolution." When this happens it puts science teachers in a difficult position that seriously impairs their ability to fulfill their teaching duties. Sadly, one even hears of a few individual creationist teachers who place their religious ideology above their professional responsibilities and who quietly use their classrooms to proselytize their creationist views. Scott mentions a case in Stanwood, Washington, where a teacher invited a creation-scientist into the class to lecture on the "latest scientific findings" about how humans and dinosaurs lived contemporaneously, and another case in which a teacher was advocating the view that the earth was very young. The failure in the secondary schools to adequately teach the key biological and geological findings and central explanatory theories such as evolution leaves students ignorant of basic public knowledge and unprepared for higher education. Moreover, students who enter college who have learned science from the Bible or creationist materials often have serious misconceptions about a whole range of facts related to evolution. They regularly misunderstand the mechanism of evolution, thinking that the theory says that organisms evolved entirely by chance. Some think that the theory says that humans evolved from the monkeys they see in the zoo, leading them to ask why there are still monkeys around. The Bible is not a science textbook and the mistakes that result from thinking that it is are sometimes even more absurd than this. Robert Root-Bernstein, a professor of physiology at a major Midwestern university, wrote of his shock the first time he taught a course on this subject when a student announced that she knew, even without looking, what the difference was between the male and female human skeletons that he had displayed for a class exercise. Males, she said, had one fewer pair of ribs than females. Her belief, of course, had come from the Genesis account of the creation of Eve from Adam's rib. Nor was she alone in her belief; five more students in the same class expressed the same view, and Root-Bernstein says that he has come to expect that at least ten percent of students will tell him that males and females differ in rib count. If people insist upon interpreting the Bible as a science textbook, then such absurdities are unavoidable and we cannot expect that complete harmony of scientific and religious beliefs will ever be possible. Johnson is right that scientists cannot contend that science and religion are so separate that the former does not have any effect on the latter. Even teaching the fact that men and women have the same number of ribs bears upon and threatens some students' religious beliefs. For those who interpret Genesis in the way that ten percent of Root-Bernstein's students do, then there is indeed a direct conflict between biology and their Christianity. But such conflicts are not confined to evolutionary biology. In an earlier era, scientific findings had contradicted Christian beliefs that the earth was fixed in the center of the universe, and creationists today also take issue with findings of geology, paleontology, physics, linguistics, and so on. What about the complaint, though, that science is philosophy? In a simple sense, creationists are right about this too. The use of the term "scientist" is actually a relatively recent development in the evolution of the English language, and people we think of as the 17th-century scientists who ushered in the scientific revolution would have called themselves "natural philosophers" and would have said that they were engaged in "natural philosophy." It is also true that science, then and now, has philosophical underpinnings (if it didn't, as a philosopher of science, I'd be out of a job), but so does every other human practice. If this were all there was to the creationists' challenge, then we should have shrugged with indifference and admitted defeat right at the beginning. However, as we have seen, creationists are making much stronger accusations, claiming that science itself is nothing but an ideology that "simply assumes" the truth of evolution and denies the existence of God "by fiat." Scientific naturalism, they say, is an arbitrary, metaphysical dogma, and a relativistic, immoral, anti-Christian, atheistic dogma at that. They impugn the intellectual and ethical integrity of any scientist who accepts and teaches evolution, asserting that it is a false, evidentially unfounded theory, and that science educators know this but promote it nevertheless as part of their intentional campaign to defend their cultural power and to attack the Christian religion. We cannot afford to let such accusations go without a reply, for they fly in the face of the truth. Just as creationists' arguments are philosophically unjustified, their insinuations about the supposedly anti-Christian motivations of scientists and science educators are similarly unfounded. No doubt there are a few atheistic science teachers who have used their classrooms to attack religion, but I have never met one. In my experience, Root-Bernstein's attitude is representative of that of the professionals who teach science, and it seems to be the only fair and reasonable way to deal with religious bones of contention: I believe just as firmly in religious freedom as I do in the scientific search for understanding. Thus, while I adhere rigorously to teaching the best science and showing how scientists recognize it as the best, I never insist that students believe scientific results. On the contrary, I encourage them to be skeptical-as long as their skepticism is based on logic and evidence. Root-Bernstein lets his students discover a bit of the evidence for evolution on their own, having them examine skeletons and X-rays directly. He notes that some of the students counted the ribs and then reported that they had verified their preconceived notion, and he said he had to stand beside them and have them repeat the procedure two or three times before they agreed that the male and female skeletons have the same number. He saves for last the clincher that he himself does have one fewer pair of ribs than his mother, not because he has had a pair removed-he has the normal twelve-but because his mother had thirteen. And he mentions the 5,300-year-old man found frozen in the Alps several years ago, who had just eleven. Chance genetic variations do indeed occasionally happen, just as evolutionary theory says, and such anatomic differences are what drive evolution, he explains to his students. He has them find homologies between human and chimpanzee skeletons that are evidence of their common ancestry, examine the underside of the bony back-plate of a tortoise skeleton to see how it could have formed from the broadening and fusing of the ribs of a reptile ancestor, and look at casts of the hooves of species leading from the four-toed Hyrancotherium to the one-toed modern horse to see some of the evidence for transitional forms. He also has them compare the relative size of human brains and female pelvis width to that of chimps, to figure out one of the reasons that sexual dimorphism is more pronounced in the former-"Bigger brains require bigger hips." But he tells them not to just trust his work, but to check the skeletons for themselves: "Take nothing for granted" he counsels his students, "That is what makes a scientist." The best education in science involves learning not just the scientific facts, but also beginning to understand how scientists reason and how they test hypotheses against the empirical evidence, which is to say, learning something of science's epistemic values. Root-Bernstein provides a wonderful model of how to get students to understand evolution and the evidence for it. This is not metaphysical indoctrination or materialist propaganda. It is simply good teaching.