A while ago, I was reading a book entitled The Reluctant Mr. Darwin which gives details about the time that Darwin was developing his theory of Evolution. I was developing an interest in Darwin the man rather than just his theory of natural selection which was why I got the book in the first place. What happened was, a member of a certain church saw the book, and we got into a short discussion. After our really short discussion about Darwin and Evolution, he said to me “It’s a theory,” putting plenty of stress on “theory.” A lot of Creationists love to use the “Evolution is a theory” argument, apparently, because that semantics technicality gives them a justification to reject it all together.
The argument that evolution is just a theory is made on ignorance of the scientific method, or methodological naturalism. This is made up of several steps such as 1) observation, 2) hypothesis, 3) testing, 4) revision, and 5) theory. — Notice that hypothesis and theory are two separate steps in the scientific method. They layperson uses the two terms interchangeably. Not so in the scientific community.
Some of the mentioned steps of the scientific method are self-explanatory, but it works like this: A hypothesis is used to explain a certain observation in nature. The hypothesis is used to make a prediction, that is, if the hypothesis predicts that X should happen, and it does, then it has support. However, you need to keep testing the hypothesis against other predictions that it makes, and if it does not pass them, then it needs to be revised. On the other hand, if it passes every test given, then it becomes a theory. — To a scientist, a theory is well supported by the evidence. It is not just a hair-brained idea that was just dreamed up. Indeed, scientific “theories” are described “proven hypothesis” and are more like scientific laws.
From this, to say that evolution is “just a theory,” Creationists are unwittingly saying Evolution is well substantiated and tested. Evolution, therefore, is only a “proven hypothesis,” it is only as useful as a scientific law. When Creationists argue along these lines, they are crossing definitions of the same term which is really not a valid line of argument. Indeed, pulling out the “it’s only a theory” card is nothing more than semantics.
Casey Luskin, who is a well-know Intelligent Design proponent at the Discovery Institute in an essay he wrote on the subject recommends against resorting to calling evolution a theory because it can imply to Evolutionists that the Creationist/ID proponent cannot cite evidence against it. — He then points out,
The “evolution is just a theory” line can come off as if the speaker really thinks “evolution is just a guess, so I don’t have to believe it if I don’t want to.” In fact, neo-Darwinian evolution as a whole is not merely a guess and most Darwinian scientists will provide reasons why they think it is the best explanation for the diversification of life.
I agree very little with Casey Luskin, but he cannot be more right in this case. When this argument is used, the implication is since evolution is a theory, there is an excuse to simply dismiss it purely our of convenience. — “It’s convenient for me, therefore I will reject it. It’s a theory, not a fact.” — Under this logic, we could dismiss other scientific theories such as germ theory, plate tectonics, the big bang, general relativity, and also gravitation. All of these are theories, and yet they have been verified by the data against observations that very well could have falsified them. — And that’s part of science right there. In order to become a theory, the proposal has to make prediction that can be falsified if it’s wrong. If later observations go against the proposal, then it has been falsified. If not, it has been verified, and it moves into becoming a scientific theory.
One of the most obvious predictions that Evolution makes is that ancient life forms in the fossil record have to show some change and transformation from certain species to others. So intermediate features between ancient fossilized creatures and modern living animals have to be discovered to verify this particular prediction. — And it so happens that fossils that seem to fit this description, in fact, exist. There are intermediate fossils between land mammals and whales, transitions between fish and tetrapods, as well as intermediate forms between ape-like creatures and modern humans.
Another prediction that is made is genetic similarity between species. And no, I don’t mean the 95 to 98% DNA similarity between humans and chimps, though there is that to. I’m talking about shared plagiarized molecular mistakes shared between different species. — Shared plagiarized errors in genetics imply a common source (or ancestor) for differing species, much like shared copying mistakes between different publications indicate that the more recent writer copied from the other.
Considering that Evolution has been tested by these predictions, and even others, common descent is just as much a legitimate part of science as any other scientific theory. And this is despite the claim made by some creationists that evolution doesn’t even meet the standard of a respectable hypothesis. In fact, there is a lot more evidence for evolution than what I have mentioned here. — The fact that there were discoveries that could have been able to falsify evolution, and that it has been verified, shows that it is more than just a hypothesis.
Scientific Laws, Hypotheses, and Theories. From Wilstar.com
Is “Evolution” a “Theory” or “Fact,” or Is This Just a Trivial Game of Semantics?, by Casey Luskin, Discovery Institute.
The Origin of Whales and the Power of Independent Evidence by Raymond Sutera. From the Talk.Origins Archive, and The National Center for Science Education.
Recent Findings: Fishes With Legs, from Devonian Times.
Human Ancestory: Species, from archaeologyinfo.com. — Also see Prominent Hominid Fossils from the Talk.Origins Archive.
Divergence between samples of chimpanzee and human DNA sequences is 5%, counting indels, by Roy J. Britten. From The Proceedings at the National Academy of Sciences.
Plagiarized Errors and Molecular Genetics, by Edward E. Max, M.D., Ph.D. from the Talk.Origins Archive, and Creation/Evolution
Is Evolution a “Fact” of Science?, by Wayne Jackson, M.A., from Apologetics Press.
29+ Evidences for Macroevolution: The Scientific Case for Common Descent, by Douglas Theobald, Ph.D. From the Talk.Origins Archive.