A couple of years ago I was leading a teacher workshop, “MYP Introduction” and one of the examples of a guiding question (now called a Unit Question) that I used happened to be about evolution. (it was ‘If Evolution is so clever, why don’t Jellyfish have hearts and lungs?’, if you really want to know) As soon as the word evolution come up one of the participants immediately retorted with “Evolution is only a theory”.
It was not particularly pertinent to the discussion at hand and it really did not add anything other than a distraction. I think I just smiled and said something like I’m not going to get into that now, it’s the Guiding Questions I want us to focus on and moved onto a different example.
It’s like a defensive mechanism that they’ve been taught, in fact I recall reading somewhere in creationist literature that whenever someone mentions Darwin or Evolution they must reply with a statement like “Evolution is only a theory”, to not do so will allow the nasty scientists to propagate truth instead of their agenda that their is some sort of debate going on about the existence of evolution. (there’s not). It’s also a classic logical fallacy of misrepresenting the argument and then trying to claim that their answer must be the correct one. (i.e. if they can ‘disprove’ evolution then the only answer must be creationism)
Anyway, here’s a couple of excellent links to learn more about both topics.
What scholars, researchers, and scientists have to say about evolution:
What creationists believe, and what scholars, researchers, and scientists have to say about the creationism: