Turning a wolf into a dog involved a number of changes, both morphological and behavioral, many of which are linked to a phenomenon common in domesticated animals known as paedomorphosis — or the retention of
juvenile traits in the adult form.
It would also explain why so many domesticated animals exhibit «neoteny»: They retain
juvenile traits as adults.
Barking is
a juvenile trait in wolves, our dogs» ancestors, and the earliest breeders probably considered it to be a desirable trait.