The American scientists were astonished to find 300-year-old trees 50 feet tall with the girth of oaks, some of them bearing apples as big and red as modern cultivars. “In the towns, apple trees were coming up in the cracks of the sidewalks,” Mr. Forsline said. “You see some of these apples and feel sure that you’re looking at the ancestor of the Golden Delicious, or the McIntosh.
Michael Pollan wrote a great article on apple biodiversity for the New York Times back in 1998. You can read it on his website. I enjoyed especially how Americans advanced the apple’s progression toward deliciousness by only being interested in hard cider.