Reports of the National Center for Science Education

Science Education, Scientists, and Faith

Anthropologist Mike Salovesh received a letter about the potential exposure of a high-school student only to evolution in classes in public schools and university. He has allowed us to reprint his reflections on the place of evolution in the social and life sciences and on the relationship between science and religion.

The concerned parent wrote:

I have some concerns about... evolution.... Is it taught as theory or fact? Can students discuss differing viewpoints? [Our child] is a very grounded young man but I worry that this may not be the right choice for his first class.

Of course, there's no way I can guess what a particular instructor will or won't do in a classroom. I can make some general points, though.

Anthropology sits at some important intellectual crossroads. Some parts of anthropology can only be done within the confines of a scientific approach. One of those parts deals with the history of our human biological nature.

When we're doing science, there are generally accepted rules of evidence that we have to follow. The central rule is that knowledge can't properly be regarded as scientific unless it can be tested against the real world. Scientific theories are attempts to explain what happens in the real world. A "theory", in this sense, says that under specific circumstances, if you do X and look at the world to see what happens next you can expect to see Y. To test the theory, we go out and do X. If we don't then see Y, we know there's something wrong with the theory. We also know that we're either going to have to modify the theory or throw it out entirely.

You ask whether an anthropology course would teach evolution as theory or as fact. Well, let me say what an anthropologist means by "evolution" in the first place. One of the simplest definitions I know says that "evolution is a change in the distribution of hereditary biological traits in a population through generations of time." Science starts by accepting the observable fact that the distribution of hereditary traits in any biological population changes through time.

If evolution is defined that way, then evolution is a fact. I've seen it myself, back when I was an Army medic. Some of the diseases we were treating were changing right in front of us as different strains of the organisms that caused those diseases developed immunity to drugs we used to cure them. There's a whole spectrum of illnesses that we used to be able to cure with penicillin, for example, that can't be today. That's known as "penicillin resistance". In fact, there have been recent mutations that have led some disease-causing bacteria to produce substances that actually destroy penicillin.

"Theories of evolution" are definitely not facts. They are attempts to explain the observable facts. Charles Darwin, who is usually credited with inventing "the" theory of evolution, didn't really do that. What he did was put forth one theory of evolution, in several parts. Some parts of Darwin's theory are as solidly based as anything we know in science; some of them were discarded nearly a century ago because they just didn't stand up to the facts of the observable universe.

Darwin's principle of natural selection was one, but only one, part of the general theory he proposed in an attempt to explain the fact of evolution. It has been subject to scientific testing repeatedly for nearly 140 years. It has never been shown to be wrong by observation of the real world. The basic idea of the principle of natural selection is that organisms that have the largest number of offspring have greater influence over the biological nature of generations that come after them than related organisms that have fewer offspring. By extension, if those organisms leaving the greater number of offspring possess any biological trait which contribute to increased survival and reproduction of those offspring, then successive generations of this organism should show greater proportions of individuals with this trait than among their ancestors.

That's exactly what we see in real populations. It's what we see in one-celled organisms; it's what we see in whales, the biggest animals on earth; it's what we see in every form of animal in between. It's what we see in every form of plant life on this planet. And, incidentally, it's what we see in human beings.

Darwin's theory of evolution didn't stop with the principle of natural selection, however. He offered an explanation of how reproduction passes traits from one generation to another - and his explanation was dead wrong. Considering that Darwin had never heard of genetics, it should be no surprise. The book where he published his theory of evolution, On The Origin of Species by Means of Natural Selection, was published more than half a century before the facts of genetics were generally known to science.

Not knowing anything about genetics, Darwin couldn't include genetic mutations in his explanations of the fact of evolution. Statistics, as a branch of mathematics, hadn't been invented when Darwin wrote, either. That's why his theory of evolution didn't make any allowances for the influence of statistical distributions in changing the frequency of biological traits in a population from one generation to the next.

I say all of this to make the point that no theory of evolution is, or can be, a fact. Darwin's theory of evolution, to be specific, is certainly not a fact. A reasonable theory of evolution is one that explains growing numbers of apparently unrelated facts, tells us something useful about those facts, and hasn't yet failed the test of observation.

Right now, we are having a very lively time in anthropology because two views of human evolution are in direct conflict. Specialists are lining up on opposing sides and hotly searching for key evidence to knock down each other's views. Since I'm in the business of teaching students to weigh the evidence and decide for themselves, I present both viewpoints in the classroom. I point to the ideas that lead people on each side to their very different views; I cite the evidence that supports them, and I cite what their opponents find wanting in the way that evidence was collected or what it means. And, on days when I do my job very well, discussion gets just as hot in my classroom as it does in scientific journals.

In this particular debate, I do favor one explanation over the other on the basis of what I know now. On questions like this, though, I try to be a scientist. That means that tomorrow I may learn of evidence that proves that the explanation I favor is wrong. In that sense, I would expect any competent person teaching introductory anthropology to encourage the discussion of differing explanations. I suspect that's not what you were asking about, however.

There are other ideas about the origins of Homo sapiens and all other living species. One set of such ideas sometimes calls itself "Creation Science". In its full-blown form, it is based on unyielding acceptance of what the Bible says about creation. It holds that it is impossible for any facts of the real world to contradict the teachings of the Bible.

You already know that I learned something in my Bible studies classes. I didn't leave religion behind me when I left high school. Many anthropologists are deeply religious. I personally look forward to a special time at the annual meetings of the American Anthropological Association, when we Quaker anthropologists hold a meeting for worship in a meeting room the Association has always provided at our request.

My religious beliefs can't be proven true by any scientific test. They are absolute, universal, and not subject to change by any external circumstance. For example, I take the commandment "thou shalt not kill" as part of the bedrock of my faith. There is no way I can prove that my belief about killing is true to the satisfaction of anyone who does not share that article of faith with me. Suppose I were to say that the rule comes from the Bible, and that the Bible is the revealed word of God. There is no way that argument would convince somebody who does not believe in God.

Indeed, I cannot imagine any facts in the real world that would convince me to give up my believe that killing another human being is wrong. That is precisely why I say that my belief about killing is not, and cannot be, a scientific conclusion. It can't be tested against observable fact. I would, therefore, be wrong if I tried to teach my college classes that science proves that my belief is the only possible one that can be held by a reasonable person.

I cannot in conscience introduce so-called "creation science" into a classroom as a viewpoint relevant to the teaching of science. It is NOT science. I believe that nearly all anthropologists whose courses are supposed to consider how humanity developed its biological nature would agree. (I have never met any who would disagree.)

My religion teaches that there is that of God in every human being. It asks that I make moral decisions about my own behavior by considering that Inner Light which comes from the presence of that of God within me. My religion also teaches me to respect the fact that another person may be perfectly sincere in denying a belief that I hold sacred, or in affirming a belief that my Inner Light would lead me to deny. It teaches me to believe that other people's beliefs about what their moral course should be are based on their faith in the guidance of their own Inner Light.

As a Quaker, I could never demand that a student abandon religious convictions. I could never demand that a student deny a religious conviction that, say, Genesis describes the actual facts about how God created the heavens and the earth. Those beliefs are a matter for the student's moral decisions, and I cannot make moral decisions for another person.

As a professor teaching science in a university classroom, I can try to make sure that what is taught and discussed there is relevant to a scientific approach to the universe. The standards of judgment I try to uphold are those that are fundamental to science. Other standards don't belong in a science classroom. The moral judgments that I base on my own religious convictions are among the other standards that have no place being taught in a science classroom. Taking time to support or to deny views that are not relevant to scientific judgment while trying to teach science is an inappropriate use of energy and resources; and it risks focusing students' attention away from the proper study of scientific subjects.
By Mike Salovesh
This version might differ slightly from the print publication.