about 68 individuals. The impact of focused selection for breeding dogs with specific physical traits created artificial genetic bottlenecks. In Ireland, they used the old Irish bulldog with different terriers and some insertion of hunting sighthound/terrier crosses. In England, there were several varieties such as the Walsall and the Cradley Heath types. Phil Drabble reported that among the various types of bull and terrier, the type from Cradley Heath was recognised as a separate breed to be named the Staffordshire Bull Terrier. In the 19th century, the Walsall type was carried by immigrants to the United States, where it served as an important component for the genetic basis of the American Pit Bull Terrier breed, through specimens such as the dog Lloyd's Pilot and the Colby bloodline, strongly combined with Irish strains. The anatomy of the bull and terrier is the result of selective breeding for the purpose of hunting, dog fighting and baiting. Descendants In “Popular and Illustrated Dog Encyclopaedia” (1934-5), Major Mitford Price wrote, “The original Bull Terrier, or Bull-and-Terrier, as he was then styled, bred for fighting in the pits, bore a far closer resemblance to the Bulldog of that day than to his terrier forbears: for there exists scores of old prints as evidence that the old Bulldog, as well as the Bull-and-Terrier had the unexaggerated (in comparison with the absurd modern standards) Bulldog head, and the legs, straight and longer, of the terrier. At the same time that the new Bull-and-Terrier made its appearance, the Bulldog fanciers began breeding their animals heavier and lower to the ground, so that the Bulldog acquired a new type. Six distinct breeds descended from the bull and terrier hybrids, five of which were recognized by the American Kennel Club (AKC) in the following order: Bull Terrier, Boston Terrier, American Staffordshire Terrier (AmStaff), Staffordshire Bull Terrier, Miniature Bull Terrier. All five breeds have also been recognized by the Canadian Kennel Club (CKC), and Fédération cynologique internationale (FCI). The American Pit Bull Terrier (APBT) is recognized by the United Kennel Club (UKC), Canadian Kennel Club, and American Dog Breeders Association. The Kennel Club recognizes four of the named breeds but does not accept the AmStaff or APBT. DNA analysis Geneticists have been able to further refine the sparse historical aspects of breed formation, and the time of hybridization. A 2017 genome-wide research study suggests the following: "In this analysis, all of