The study found distinct genetic clusters within modern dogs that largely corresponded to phenotype or function. These included spitz-breeds, toy dogs, spaniels, Mastiff-like breeds, small terriers, retrievers, herding dogs, scent-hounds, and sight-hounds. There were 17 breeds that conflicted with phenotype or function and these were thought to be the result of crossing some of the other phenotypes. As in a 2004 study that found 9 ‘ancient breeds’ to be genetically divergent, the study found 13 breeds that were genetically divergent from the modern breeds: the Basenji, Saluki, Afghan hound, Samoyed, Canaan dog, New Guinea singing dog, dingo, Chow Chow, Chinese Shar Pei, Akita, Alaskan malamute, Siberian husky and American Eskimo dog. Results also indicated that the Basenji had recent admixture with Middle Eastern wolves.
Other breeding bills lump small breeders in with large commercial breeders. Small breeders are in no any way able to meet some of the kennel requirements written for large commercial establishments because they typically keep their dogs in their home as pets.
Dogs have been selectively bred for thousands of years, sometimes by inbreeding dogs from the same ancestral lines, sometimes by mixing dogs from very different lines. The process continues today, resulting in a widening in appearance without speciation, "from the Chihuahua to the Great Dane."
No one is suggesting that people should not get a dog from a shelter or rescue if that’s what they want to do. Many breed clubs were among the first dog rescue groups in the U.S. Breeders love dogs and believe in rescue. But people should also have the option to purchase a purebred dog from a dedicated breeder without harassment or guilt. And breeders should be able to breed their dogs without punitive laws.