Before we can have any meaningful discussion on this subject, we must clearly and concisely define what we mean by the terms “creation” and “evolution.”
What, then, is evolution? Evolution has a wide range of definitions, varying from the very scientific definition, “a process that results in heritable changes in a population spread over many generations” to the very vague generalization “descent with modification” (or even “change over time”). (See What is Evolution?, by Laurence Moran from the Talk.Origins website for a discussion by an evolutionist on the definition of evolution.) Upon inspection, though, it is easy to see that neither of these definitions accurately conveys what is commonly thought of when the word “evolution” is used. The first definition can be more accurately applied to the principle of natural selection (which is completely different from evolution) and includes nothing of the idea of life coming from non-life. “Descent with modification” can describe anything from “goo to you via the zoo” evolution to what happens in succeeding generations of a family to the effect of throwing a banana off the roof of a three-story building.
Educated proponents of evolution insist upon the first definition, pointing out that the origin of life is a separate issue, and the view that life comes from non-life is more accurately called a biogenesis. The general public, on the other hand, uses evolution loosely and freely, applying it to everything from organisms to the cosmos to language to technology. But while both definitions capture a particular aspect of the idea, neither describes it fully or accurately.
For instance, to deny that evolution includes the origin of life is misleading, since Darwin himself titled his book the Origin of Species, and talked about the first simple cells arising out of a primordial slime. Furthermore, textbooks, articles, or general books that deal with evolution commonly contain this idea of the first simple life arising spontaneously from non-living substances. On the other hand, to refer to any change over time as evolution is also incorrect, since the basic theory deals only with the biological evolution of living organisms. Nonliving substances cannot evolve. Furthermore, all change over time in biological entities is not evolution. Natural selection, for instance, is a well-documented principle in which the fittest animals in a species survive to pass on their genes, which provides the potential for great variety within a species.
It should be noted here that natural selection is not evolution. Charles Darwin was not the first to notice the principle of natural selection—it was first described by the creationist Edward Blythe. Even today, natural selection is an important part of creationist models. What Charles Darwin did was take the principle of natural selection and extrapolate it out to the point where it was capable of producing unlimited change, even to the point of creating entirely new species, genera, families, etc. In other words, natural selection is the means by which evolution is proposed to occur—it is not evolution itself. See the article, Muddy Waters, by Carl Wieland of Answers in Genesis for more information.
But while evolution itself applies only to biological entities, it is impossible to deny that there are a host of other theories about the origin of the universe that have become inextricably tied to this one concept—theories such as the Big Bang (“cosmological evolution”), uniformitarianism (“geological evolution”), a very old universe and earth, and other theories. Furthermore, evolution is almost automatically associated with more philosophical views, such as atheism, agnosticism, relativism, and materialism.
In other words, while a strict definition of evolution would refer exclusively to biological evolution, there is a large amount of baggage that has become attached to the term that cannot be ignored in any meaningful debate on the subject. Even evolutionists recognize that the public’s conception of evolution contains far more than the observable biological theory that they use as its definition. Furthermore, in most of the court cases concerning the teaching of evolution, the main issue is not the current biological process but the question of origins and the existence of God. In addition, when creationists debate evolutionists, the current biological process is only one area of disagreement. In any creation/evolution debate, you are likely to hear a wide range of issues discussed, from biological evolution to geological processes to the origin of life and the cosmos to the age of the earth to the existence of God, and many other issues. Therefore, to ignore all of these issues in a discussion such as this would be inappropriate, due to the universal nature of the issues automatically associated with the word “evolution”.
To come to a clear, concise, reasonable definition of evolution, then, we can say that evolution is the view that everything came from nothing—the idea that nature created itself. It includes such things as: the Big Bang theory as the origin of the cosmos, uniformitarianism as the default process of geology, a biogenesis as the means for the origin of life, biological evolution as the means behind the present variety of living organisms, and by implication the belief that nature is all there is (materialism; i.e., there is no God or supernatural) and that there are no moral absolutes (relativism).
Again, some evolutionists will disagree with this definition, but it is impossible to deny that those and other theories are firmly, automatically, and inextricably associated with evolution, both in the general public and in the creation/evolution debate.