Many creationists probably think the theory of evolution isn’t scientific. It actually is, but in order to understand what that means, we need to ask what makes any theory scientific. We can label an idea as “scientific” if it can be studied using the scientific method.
If we have an idea, several approaches can help us decide whether it’s correct. One way is to use reason to decide whether it’s true. We can call this the philosophical approach. Another way is to study the Bible to find out whether it’s true. This would be a religious approach. Finally, we can think of observations and experiments that may help us to determine whether the idea is correct. This is the scientific approach. Let’s compare these three approaches.
Suppose we want to know how many teeth a horse has in its mouth. If we just think about the answer, how do we know our conclusion is correct? We need to compare our thoughts against some kind of standard. If we have no such standard, our thinking is just a wild guess.
We could also search the Bible to find out how many teeth a horse has in its mouth. The problem is that the Bible was not given to answer such questions.
If we wonder how many teeth a horse has, the best way to answer the question, obviously, would be to open the horse’s mouth and count them. And when we do that, we’re using the scientific approach.
How science works
The scientific method can be described with the following sequence of events. A scientist has an idea, called a hypothesis, and then he thinks of observations and experiments that will test the hypothesis. The results may indicate that his hypothesis is false, or they may support it. Another possible outcome is that the answer will remain unclear, and he will have to design additional observations and experiments to better test his hypothesis.
One thing we can be sure of: science will not provide us with absolute proof or disproof. We may think we have proof, but it’s always possible that new evidence will change the picture. I sometimes tell my science students that half of what I am teaching them is untrue, but they’ll have to wait for new scientific discoveries to know which half is wrong.
Some years ago, the scientific evidence indicated that there were ten species of chipmunks in California, but new evidence has demonstrated the existence of 13 species. In molecular genetics, a central dogma used to be that each gene on our chromosomes directs the making of a single protein. However, new discoveries have shown the process to be significantly more complicated.
The list of such changes in scientific understanding is endless. Science makes many significant discoveries, but it also keeps showing us that things we once were sure of are actually incorrect. We just didn’t have enough evidence at the time to understand that.
There are some questions that science can’t answer because they can’t be tested, no matter how much research is done. For example, when Jesus lived on earth, did He really perform miracles? Try to devise an experiment to test that idea. You may be absolutely sure that He did perform miracles, but your belief can’t be proved by science.
Now back to our question about the theory of evolution. I’ll begin by considering the meaning of the word evolution. One basic definition of biological evolution is “change through time.” Animals and plants change as their genetic systems allow them to adapt to different environmental conditions.
A simple example is the beaks of finches on the Galapagos Islands. As the climate changed over a period of several years, changes occurred in the finches’ food supply. Finches with small beaks had less chance of survival, and the average size of finch beaks changed to accommodate the available food. Then, as the climate shifted back to its previous condition, the available food also changed, and the average finch beak size returned to what it was before the climate shift. This is an example of microevolution—change within a species— which generally occurs through mutations and natural selection.
Can microevolution be studied using the methods of science? Yes, it can. Many scientists conduct research on microevolution by observing how creatures change as the environment changes. They are studying processes that can be observed and documented.
The theory of evolution includes another concept called macroevolution— the idea that all life-forms evolved through long ages of time from a common ancestor. This part of evolution says that toads, sparrows, worms, cabbage plants, palm trees, lobsters, and scientists themselves all evolved from a common, one-celled ancestor.
What about macroevolution— the larger changes through time and descent from common ancestors? Can this be studied using the methods of science? Yes, scientists use many types of evidence to develop and test hypotheses about evolution from common ancestors.
Both types of evolution are scientific in the sense that they can be studied using the methods of science. However, there is a difference between them. At least parts of the microevolution process can be observed, but macroevolution— the theory that different types of animals descended from common ancestors in the distant past—cannot be observed. Research on common descent does make use of scientific evidence, but it is much more dependent on assumptions in order to interpret that evidence.
The most important assumption that is generally accepted by scientists is that there have never been any miracles, any supernatural acts, in all of history. Everything in nature can be explained by the laws of nature that have been discovered. This assumption is called “naturalism.”
Using this assumption, scientists will always interpret evidence about origins according to the theory of common descent. The evidence can be interpreted in various ways, but in the naturalistic worldview, the only interpretations that will be accepted are those based on the descent of all organisms from a common ancestor through evolution.
Many of us want to know more—not just whether the theory of evolution can be studied with science but whether it’s true. Sometimes the term scientific is used in a way that implies that if something is not scientific, it isn’t true. Because Jesus’ miracles can’t be tested by science, does that mean they aren’t true? That isn’t a reasonable conclusion. Science can’t show whether Jesus’ miracles did or didn’t happen.
Can the assumption of naturalism be tested by the methods of science? If it could, it would no longer be an assumption. The supposition that there were no supernatural acts involved in the origin of life-forms (that is, no creation) is a belief about the past. It cannot be tested by observations or experiments. For this reason, the assumption is an arbitrary philosophical choice, not a choice that rests on science. There’s considerable evidence that’s claimed to support evolution over millions of years, but different worldviews can lead to different interpretations of the same evidence. The difference lies in the interpretations and in the assumptions on which those interpretations depend.
To illustrate this difference in worldviews and the resulting interpretations, consider this example: worms and scientists have the same biochemical processes occurring in the cells of their bodies. Naturalistic scientists think this indicates that they evolved from the same common ancestor, but it could also mean that the same Creator designed both, using the same biochemical mechanism to maintain life in their cells. The difference between those two interpretations—evolution and creation—cannot be tested by the methods of science, because they are based on assumptions about what happened in the past.
In the study of microevolution, we can often “open the horse’s mouth and count the teeth.” But when we ask if we evolved from bacteria and worms, we are asking a question about ancient history, and no scientist was there to “open the horse’s mouth.”
We can ask God for the answer, and in this case, it’s a spiritually significant question that the Bible does address. Genesis says that God created the world and all living things in it. The only other option to answer the question is philosophical in nature. We can think about the limited evidence we have and decide, in our own minds, that the assumption of naturalism is correct. But that doesn’t necessarily make it so.
So is the theory of evolution scientific? Yes, it is in the sense that it can be studied using the methods of science. So does its status as a scientific theory make it a demonstrated fact? Many books written by scientists stoutly assert that evolution over long ages is as much a fact as is gravity. However, those claims are not realistic if one possesses a proper understanding of the scientific method. Parts of evolution, especially microevolution, are well documented and seem to be essentially true, although there still may be much to learn before we understand even that part correctly.
But macroevolution, especially its claims about ancient history and the origin of life-forms, is in a different category. Science can study these claims and devise hypotheses, but those hypotheses can never be rigorously tested by science. We were not there, and our interpretations of the ancient past are only as good as our assumptions.
For many of us, the Word of God is a more reliable guide to understanding ancient history. God was there when life was created, and He “counted the horse’s teeth” and told us the answer. The Bible does address the topic of origins because God knew that it’s important for us to know where we came from, why we are here, and where we are going.
The question “Do I know Jesus?” may not seem very scientific, and some may not consider it relevant to our discussion about evolution. However, I submit that it is the most important question of all. Do we give more credence to contemporary scientific interpretations than to God’s Word, or do we know Jesus well enough to have confidence in His communication to us through the Bible?