Skewed Science

A Review of Teaching about Evolution and the Nature of Science


Mark Hartwig, Ph.D.

I had set out on a journey, with no other purpose than that of exploring a certain province of natural knowledge; I strayed no hair's breadth from the course which it was my right and my duty to pursue; and yet I found that, whatever route I took, before long I came to a tall and formidable-looking fence. Confident as I might be in the existence of an ancient and indefeasible right of way, before me stood the thorny barrier with its comminatory notice-board--"No Thoroughfare. By Order. Moses."

--Thomas Henry Huxley (a.k.a. "Darwin's Bulldog")

The eminent British scientist Thomas Huxley had a bone to pick with organized religion. To hear him tell it, religion was always getting in the way of free inquiry and scientific progress. He set out to "break the fence down and go through it."

And break it down he did. More than anyone else--even Charles Darwin--he spread the "gospel" of naturalistic evolution.

In place of the old fence, however, a wall has sprung up--the wall of naturalism. It was built to ensure that no one questions the all-sufficiency of natural forces to create our world.

The latest brick in the wall is a new guidebook from the National Academy of Sciences (NAS), titled Teaching about Evolution and the Nature of Science. Ostensibly written to help science educators, textbook publishers and policy makers resist pressure from anti-evolutionists, the handbook is actually an apologetic for teaching a dogmatic evolutionism in the public schools.

If this guidebook became policy, which is the intent of the authors, teachers would have to teach a skewed science curriculum that misrepresents broad areas of biology. Worse, they could find themselves in the position of promoting the guidebook's vision of correct religious belief.

Problems? What Problems?

Undergirding the guidebook is the belief that naturalistic evolution is a fact that must not be disputed by either teachers or students. Early in the book, the authors state:

Those who oppose the teaching of evolution in the public schools sometimes ask that teachers present "the evidence against evolution." However, there is no debate within the scientific community over whether evolution occurred, and there is no evidence that evolution has not occurred.

They even go so far as to assert, "It is no longer possible to sustain scientifically the view that the living things we see today did not evolve from earlier forms or that the human species was not produced by the same evolutionary mechanisms that apply to the rest of the world."

The authors back their claim with several "compelling" lines of evidence, including change in the fossil record, the findings of molecular biology, the presence of similarities among different species, the development of antibiotic resistance in bacteria, changes in the shape and size of bird beaks, and so on.

But in order to build their case, the authors have had to make unwarranted conceptual leaps, without warning the reader. They've also had to be very selective about the evidence they use.

The Meanings of Evolution

To understand the guidebook's flaws, it's necessary to understand what the authors mean when they use the word evolution.

Throughout the guidebook, the authors use the word evolution in at least three different ways. The first and most general meaning is "change over time." In this sense, to say that evolution has occurred is to say that things are different now from what they were in the past: Galaxies change, stars change, the solar system changes and so on. This meaning is so broad, few people could object to it.

The second meaning is "descent with modification," the idea that "living things share common ancestors." Here, evolutionary change means the emergence of new species from older ones. According to the guidebook, "Scientists most often use the word 'fact' to describe an observation. But scientists can also use fact to mean something that has been tested or observed so many times that there is no longer a compelling reason to keep testing or looking for examples. The occurrence of evolution in this sense is a fact. Scientists no longer question whether descent with modification occurred because the evidence supporting the idea is so strong."

The third meaning concerns the mechanism of biological change--the particular process through which evolution in the first two senses occurred. Used in this sense, evolution refers to random genetic variation and natural selection--or "survival of the fittest." Another term for this meaning is neo-Darwinism, or contemporary Darwinism.

In this view, nature acts like a breeder, scrutinizing every organism. When useful new traits appear, they are preserved and passed on to succeeding generations, while harmful traits are eliminated. Over time, these small changes accumulate until organisms develop new limbs, organs or other parts. Eventually, organisms may change so drastically that they no longer resemble their original ancestor.

Referring to this third meaning of evolution, the guidebook states, "Evolution is the only plausible scientific explanation that accounts for the extensive array of observations summarized above. The concept of evolution through random genetic variation and natural selection makes sense of what would otherwise be a huge body of unconnected observations."

In other words, the authors are promoting the Darwinian mechanism as the true creator of everything in the living world.

Missing Evidence

Evolution in the sense of"change over time" is so vague an idea that it isn't worth disputing. But how good is the evidence for evolution in the other two senses?

Let's take a look at evolution in the third sense: contemporary Darwinism.

The case for contemporary Darwinism is much poorer than the authors let on. For one thing, there's simply no evidence that random genetic variation and natural selection can produce the kind of massive change that the authors claim. These mechanisms may help bacteria develop resistance to antibiotics, or cause changes in the shape and size of bird beaks. But it's an enormous leap to say that these same processes can produce new organs, structures or body plans--let alone the entire array of living organisms we see today.

In fact, there's good evidence that contemporary Darwinism cannot do the job. One example comes from the high-tech world of molecular biology. The authors claim that molecular biology provides compelling evidence for both contemporary Darwinism and descent with modification. In particular, molecular biology has shown that all living things share the same genetic code--which the authors say is "powerful evidence for the interrelatedness of living things."

What's more, say the authors, "the advent of molecular biology has made it possible to read the history of evolution that is written in every organism's DNA. This information has allowed organisms to be placed into a common evolutionary family tree in a much more detailed way than possible from previous evidence."

That may sound impressive. But part of it is flat wrong. It's simply not true that all organisms share the same genetic code. Biologists have known for over a decade that many organisms have genetic codes that differ from the so-called "universal" code. The single-celled Paramecium, for instance, found in pond water and countless high school laboratories, has a different genetic code than most organisms. So do species of the yeast Candida, which commonly infect people with weak immune systems. And several other organisms, such as the green algae Acetabularia, or the bacterium Mycoplasma, also have variant codes.

This is a stunning error, considering that the working group that produced the guidebook included a prominent cell biologist who is president of the National Academy of Sciences.

Errors aside, the authors also neglect to tell us that molecular biologists have found powerful evidence against contemporary Darwinism. Some of this evidence is summarized in biochemist Michael Behe's recent book, Darwin's Black Box.

When Darwin laid out his theory in 1859, he said, "If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find ... no such case."

Behe, however, has shown that even some of the simplest systems in a single cell cannot be produced in such a manner. These systems exhibit what he calls "irreducible complexity."

According to Behe, "An irreducibly complex system is one that requires several interacting parts to function, where if you remove or destroy one of the parts, then the function is also destroyed."

An everyday example is a mousetrap. A mousetrap has five parts: a platform, holding bar, hammer, catch and spring. When assembled there's no gradual improvement of function. It doesn't work until every part is in place. The same thing is true inside a living cell. Many of its systems just won't work unless every part is there.

Consider what's involved, for example, in moving a protein from one part of the cell to another. Proteins don't just float around freely inside of cells. They have to be moved from one compartment in the cell to another--from where they're made, to where they're needed.

Cells have two fundamentally different ways of doing this: gated transport and vesicular transport. In gated transport, the compartment wall is equipped with a "gate" and a chemical "sensor." If a protein bearing the right "identification tag" approaches, the sensor opens the gate and allows the protein to pass through. If one with the wrong tag approaches, the gate stays shut.

Note the irreducible complexity in even this simple example. All three components--the gate, the sensor and the tag--must be in place. There's no way to produce the system in a gradual, Darwinian fashion.

If the tag is missing, the gate won't open. Ditto if there's no sensor, or if there's just a solid wall. And if there's a hole where the gate should be, proteins will pass through haphazardly.

Vesicular transport is even more complicated, requiring many more components to work. Nor is such complexity limited to cell transport. Other examples include blood clotting, the chemistry of vision, the immune system and the structure of bacterial flagella--long filaments that some cells use as propellors.

Such systems cannot be produced in the cumulative fashion that contemporary Darwinism demands. To get any function out of such a system, it has to be produced all at once--which looks too much like a miracle for most scientists.

This is just one example of how the guidebook looks at only part of the evidence, while ignoring, misrepresenting or pooh-poohing the rest.

What about descent with modification? Can that be considered a fact if Darwinism is disproved? The books authors state, "Some of the details of how evolution occurs are still being investigated. But scientists continue to debate only the particular mechanisms that result in evolution, not the overall accuracy of evolution as the explanation of life's history."

What the authors fail to acknowledge, however, is that without a mechanism there can be no "fact" of evolution--except for the trivial examples of antibiotic resistance in bacteria and the like. The evolution of new organs or body plans cannot be observed in the same way we can observe, say, the fact of gravity. The latter can be demonstrated by dropping a pencil. No such observation can demonstrate the former.1

Pontificating on Religion

The most troubling aspect of the guidebook is not how it misrepresents the evidence for evolution. It's how the authors meddle with religion.

Addressing the question of whether someone can believe in God and still accept evolution, the authors assert, "Many do. Most religions of the world do not have any direct conflict with the idea of evolution."

The authors further assert that people who object to the religious implications of naturalistic evolution are mistaken: "At the root of the apparent conflict between some religions and evolution is a misunderstanding of the critical difference between religious and scientific ways of knowing. Religions and science answer different questions about the world." Science deals with objective facts, while religion answers questions about whether there is "a purpose to the universe or a purpose for human existence." Therefore, scientific findings can be no threat to religion--and parents need not worry about evolution undermining their children's religion.

But this is a bogus distinction. Although religion and science are distinct enterprises, there is a great deal of overlap between them. Apart from religious liberalism, most religions do not limit themselves to questions about the purpose of life, but purport to answer questions of facts. For example, both Christians and Muslims believe that the virgin birth of Jesus Christ is a fact. Even if hundreds of millions of Christians and Muslims doubted that claim, that would still leave billions who believe it.

Enormous numbers of Christians also believe that Jesus is the Son of God, that He was really crucified and that He really rose from the dead. And, of course, they believe that He really did create the world. Such people do not misunderstand "the critical difference between religious and scientific ways of knowing." They simply don't fit the modernist view of religion approved by the guidebook's authors.

Conclusion

As a guide for policy, the NAS booklet is deeply flawed. Its dogmatism and skewed treatment of evidence are poles apart from what most people expect of science education. In fact, it's only real use is in a class on critical thinking--as grist for the students. Any other use is simply unconscionable.

Reference

1. To be fair, the authors state that "This publication does not attempt specifically to refute the ideas proffered by those who oppose the teaching of evolution in public schools." This does not justify, however, ignoring or dismissing important contrary evidence.

Mark Hartwig is editor of Teachers in Focus magazine. For ten years he was managing editor of the scholarly journal, Origins Research, now published as Origins & Design.