It's fascinating that you can say this with little comment, but if I say the exact same thing it leads to a sprouting of multiple irrelevant tangents about Cantor, semantics, ontology, the definition of "true", the definition of "right", etc, etc, etc, none of which actually alter the substance of what I said - which is that all scientific theories are held tentatively.
and Evolutionary theory is not one of the less secure.
This may be relevant in your debate with others, but it's not relevant to the article about the disclaimer. By speaking of "evolutionary theory" you concede the only relevant point, which is that "evolution" (no matter how secure) is a theory, which is what the disclaimer says (by my reading of the article).
As soon as your notion is extended to cover such less secure theories as stellar evolution, continental drift, and rotational inertia under gravity, than I'll have no problem with your prescription
Are you saying that the textbook in question does not clearly state that the preceding are "theories" already? I'm curious, let me know. I was always indeed taught that continental drift/plate tectonics as explanation for continents was a theory, not Truth, for example. Your point may be completely moot.
You know what's truly ironic: there would be a simple and straightforward way to shut the mouths of the "creationist side" of the argument (I'm including myself even though I'm not a "creationist" per se). Would you like to know what it is? Here goes:
Just tell us knuckle-dragging imbeciles, "The textbook in question ALREADY DOES explain that evolution is a theory! So a disclaimer is redundant."
That's ALL you would have to say. That's ALL the vigorous opponents of the disclaimer would have to say. It would shut our traps. We would have to shut up.
So why don't you say it? Why doesn't anyone say it?
Could the reason be that the textbook in question DOESN'T already say that evolution is a theory?
But that would be quite odd. Why wouldn't the textbook say what is obvious and what everyone, especially scientists, agrees upon?
In fact, any honest scientist would have to agree that for a textbook not to present "evolution" as a theory is, well, scandalous.
Maybe. Given all the fuss of late, certainly. However, let me point out that one of the things elementary textbooks ought to strive for is simplicity of presentation. An eight-hour dialog on the present controversies regarding the epistimological limits of scientific reasoning, might not be the cat's pajamas for getting an eight year old interested in science.
Personally, I'd be more than content to leave biology off the agenda until high school.
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By the way, I expect nobody tells you for sure because nobody remembers. When people have chimed in on this discussion whose kids had current textbooks, so far, I don't remember a reported case of disclaimer-failure.