From what I understand, apples are actually notorious for creating new varieties of themselves with no provocation whatsoever. It's basically impossible for them to breed "true" without grafting or cloning. But by the same token, almost all the resulting varieties aren't very good for eating for one reason or another.

Good article. But I am from New England and here the apple industry is dying because of imports (perhaps from the Northwest, but I really don't know). With the dying are a lot of my favorites: cortland, empire, and others. They are still available in stores, but the quality is not what it used to be. Plus, they are all beat to shit.