Cats are the best demo

(As demonstrated by Schrödinger.)

Based on a real kitty! Ours also has a "dilute" mutation (in a myosin gene) causing a failure in transporting melanocytes to the exterior of cells - resulting in gray and cream rather than black and orange spots. She's also a Ragdoll - the pictures in the comic are no exaggeration.

Yes, I am responsible for the pictures of kitties on the X-inactivation and Genetics articles. :-)