The fourth argument that "evolutionists" shouldn't use is the argument that "doubting Evolution is like doubting gravity."
This isn't an argument for Evolution, per say, it's merely an analogy. The fundamental forces that govern both Evolution and gravity are theories (because that's what theories are, models of how an observable fact works). Both are supported by a wide-array of evidence, otherwise they would cease to be acceptable theories. So, when we say that doubting Evolution is like doubting gravity, we're saying that both are substantiated by evidence and that it would be silly to ignore some facts and accept others (we actually know more about Evolution than we do gravity).
The example that AIG uses is one out of pure ignorance (and probably should belong on the list of arguments Creationists avoid).
"Take a pencil or pen. Hold it in the air. Then drop it to the floor. That’s gravity. Next, make a single-celled organism—like an amoeba—turn into a goat. Go ahead. We’ll wait. . . . No? As you can see, there’s a fundamental difference between operational science, which can be tested through repeatable experimentation, and historical science, which cannot."
First off, you can't MAKE a single celled organism instantly turn into a complex multi-celled organism (it takes billions of years). You simply don't have the time. Is it possible? Yeah, we have the evidence that shows how single celled organisms could have evolved into multi-celled organisms (it doesn't have to be a goat, of course). Just because you can't watch an amoeba turn into a goat doesn't mean that evolution isn't true, it's just a long process. We can look back in time, essentially, and see that some kind of evolution obviously took place because of the evidence the process left behind, but we can't evolve new species from amoebas. Evolution is operational science, which operates not only in Biology, but in many other scientific disciplines. There's nothing historical about it, more and more discoveries are being made every day: all of them support evolution.