Buggman: I don't have to come up with a mechanism to explain an unproven process.
So you don't want to come up with the species limitation process that creationists believe exists, which limits micro evolution from becomming macro evolution? Fine. Science doesn't believe there is such a thing anyway.
That's why science accepts evolution.
So why then are fruitflies still fruitflies? Evolutionists need to prove that macro-evolution happens by replicating it in the lab with a short-lived organism, not demand that someone else prove that it cannot happen.