The fallacy of equivocation is an extremely common fallacy in the Creation vs. Evolution debate. Equivocation is the use of ambiguous language in order to either avoid commitment or to mislead the audience. There are two very important terms in the Creation vs. Evolution debate. These two terms are, not surprisingly, Creation and Evolution. No one knows what we're talking about if we do not define these two very important terms. Unfortunately, they're both extremely ambiguous.
Evolution has a wide range of meanings. It can refer to the origins of the universe and all that is in it. It can include abiogenesis. It can be referring to everything that has supposedly happened since abiogenesis supposedly happened. And there's the completely useless "change over time" or "descent with modification" definitions, which as we'll see in a moment, are useless in this discussion.
But typically, when discussing Evolution, this ministry uses the definition given by Gerald Kerkut in Implications of Evolution: "the theory that all the living forms in the world have arisen from a single source which itself came from an inorganic form." By giving this definition, my audience knows exactly what I'm saying. When I say, for example, "Evolution is not science", an Evolutionist can no longer respond with "so you don't think species change over time?"
Just like Evolution, Creationism has a wide range of applications. It could apply only to the idea that a god of some form created the universe in some way. It could apply to Theistic Evolution, the idea that God directed Evolution. We could completely cut out the flood and say that only the first 6 days of history matter. Or why involve the Bible at all? Muslims believe Allah is a creator.
Thus, as a Creationist, I must also define Creationism. Creationism, simply put, is "the belief that the book of Genesis, particularly the first 11 chapters, accurately describes the origins of the heavens and the earth". Once again, no ambiguity. Now let's reverse the roles for a moment. Let's pretend I haven't given the above definition of Creationism and instead decided to define Creationism as just "the belief that intelligent beings create things." Let's also imagine an Evolutionist says "Creationism is false", and I then turn around and say "so you don't believe a human being made my laptop?"
The above scenario would be equivocation. Just because an Evolutionist acknowledges the fact that human beings make laptops does not mean they believe a single word of Genesis. In the same way, just because a Creationist acknowledges the fact that species change over time does not mean they believe any living organism can evolve into anything other than its kind.
If Evolution is just "change over time", most Creationists are Evolutionists. If Creation is just "the belief that intelligent beings create things", most Evolutionists are Creationists. You see the problem. The equivocation of Evolution is designed to give Evolution, as a theory of origins, a free ride on the back of "evolution", as a scientifically observed feature that offspring do not perfectly resemble their parents. One has to wonder if Evolution could survive without this fallacy.