And yet, after thousands of generations of changing their diets, bombarding them with radiation, altering their atmospheres, and so on, fruitflies remain fruitflies.
As always, the evolutionist must confuse the distinction between micro-evolution (variations within a species, such as breeding dogs) with macro-evolution (breeding dogs until they become cats). The former is well-established--the latter is sheer speculation that is so unsupported by the fossil record that Stephen Jay Gould had to invent the theory of punctuated equilibrium to explain away the lack of transitional fossils.
When you have bred a dog into a cat, or a fruitfly into a hornet, let me know. Until then, claiming that (macro-)evolution is as established as gravity (which I just proved by dropping my pen and watching it fall to the floor--want to see me do it again?) is a statement of metaphysical faith, not one of science.
So what is the mechanism that limits your "micro" evolution from becoming "macro" evolution?
Creation "scientists" stopped doing research on their own after they gave up trying to prove Noah's flood and a young earth back in the 50's.
Here's a chance for them to resume research. Let them find and demonstrate whatever it is that limits evolution to a "kind".
My bet is they can't. And further, I don't think they will try, because they already know they will fail. Instead, they, and you, will offer excuses as to why such research is unnecessary.