The majority of living things have some form of symmetry. Many mammals and fish have bi-symmetry, and anemones, starfish and jellyfish (among others) have radial symmetry. However, there usually are many small or major differences that make them not perfectly symmetrical. Is it possible for something to evolve to be 99% perfectly symmetrical, possibly even spherically?
Edit: I'm talking about something big, maybe as large as a cat or dog, not something tiny (ie. cocci bacteria).