|thanks british library (PD)|
Wolves: upright, pointy ears. Most dogs: floppy ears.
Hares and wild rabbits: Ears up. Many domesticated rabbits: Soft floppy ears.
Boars/pigs? Check. Goats/goats? Check. Cats/Cats? Um - that one doesn't work; they're all up and pointy, wild or no. (Cats: Throwing wrenches in the works since...ever.)
Still, the ear phenomenon is prevalent enough that it sparks curiosity. And when I ran across this short, entertaining animation on the subject at NPR, I learned the latest research on why those ears (and those shorter muzzles and those spotted coats). A publication by Charles Darwin is namechecked: "The variation of plants and animals under domestication." Want to idly flip through some of that? You can find an introduction and several editions here.