Dog breed

Chihuahua mix and purebred Great Dane

Dog breeds are dogs that have relatively uniform physical characteristics developed under controlled conditions by humans, with breeding animals selected for phenotypic traits such as size, coat color, structure, and behavior.[1] The Fédération Cynologique Internationale recognizes over 400 pure dog breeds.

Other uses of the term breed when referring to dogs may include pure breeds, cross-breeds, mixed breeds and natural breeds.

History

Tesem, an ancient Egyptian sighthound

Archaeology has revealed dog remains of various sizes but there does not appear to have been distinctive breeds until 3,000-4,000 years ago when greyhound-type dogs were depicted on pottery and paintings in Egypt and Western Asia. Mastiff-type dogs were kept for guarding and hunting, and short-legged dogs were also bred. By Roman times, most of the breed-types known today were well-defined and their qualities and functions recorded. Dog breeds proliferated in Europe during the Middle Ages 700 years ago.[2] Most modern dog breeds are the products of the controlled breeding practices of the Victorian era (1830-1900),[3][4] and the accurate documenting of pedigrees with the establishment of the English Kennel Club in 1873 in imitation of other stud book registries for cattle and horses.[5]

For early depictions of dogs in art, see early history.

Genetic evidence of breeds

Wolf


Shar Pei

Shiba Inu

Chow Chow

Akita Inu

Basenji


Siberian Husky

Alaskan Malamute


Afghan Hound

Saluki

other breeds in the study






Cladogram of 9 breeds that are genetically divergent from others[6]

Ancient dog breeds

Ancient breed of dogs was a term once used for a group of dog breeds by the American Kennel Club,[4] but no longer.[7] These breeds were referred to as "ancient breeds", as opposed to modern breeds, because historically it was believed that they had origins dating back over 500 years. In 2004, a study looked at the microsatellites of 414 purebred dogs representing 85 breeds. The study found that dog breeds were so genetically distinct that 99% of individual dogs could be correctly assigned to their breed based on their genotype, indicating that breeding barriers (pure-bred breeding) has led to distinct genetic units. The study identified 9 breeds that could be represented on the branches of a phylogenetic tree which grouped together with strong statistical support and could be separated from the other breeds with a modern European origin. These 9 breeds had been referred to as "ancient breeds", as opposed to the modern breeds. The study found that the Pharaoh Hound and Ibizan Hound were not as old as believed but had been recreated from combinations of other breeds, and that the Norwegian Elkhound grouped with the other European dogs despite reports of direct Scandinavian origins dating back 5,000 years.[6]

Dog types

See further: Dog type

The spread of modern dog breeds has been difficult to resolve because many are the products of the controlled breeding practices of the Victorian era (1830–1900).[3][4] In 2010, a study looked at 48,000 Single nucleotide polymorphisms that gave a genome-wide coverage of 912 dogs representing 85 breeds.[8]

The study found distinct genetic clusters within modern dogs that largely corresponded to phenotype or function. These included spitz-breeds, toy dogs, spaniels, scent-hounds, 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.[8]

The study found that there were three well-supported groups that were highly divergent and distinct from modern domestic dogs. The three groups were

Basal breeds

In 2012, a study looked at 49,000 Single nucleotide polymorphisms that gave a genome-wide coverage of 1,375 dogs representing 35 breeds, 19 wolves, and previous published genetic signatures of other breeds, giving a total of 121 breeds covered. The study found a deep genetic split between old-world and new-world wolves, and confirmed the genetic divergence of 13 breeds from a 2010 study plus another 3: the Eurasier, Finnish Spitz and Shiba Inu. The study referred to these 16 breeds as Basal breeds, as opposed to ancient breeds, as they exhibited genetic divergence but not all of them were historically considered to be "ancient breeds". The study found that modern breeds only emerged in the 19th Century and that claims of their antiquity are based on little or no historical or empirical evidence. The study indicated that throughout history, global dog populations experienced numerous episodes of diversification and homogenization, with each round further reducing the power of genetic data derived from modern breeds to help infer their early history. Of the basal breeds, the American Eskimo Dog and Eurasier were the very recent product of cross-breeding other basal breeds. Most basal breeds have hybridized with other lineages in the past, and if those other lineages were other basal breeds then a basal genetic signature remains. The combination of introgression and past population bottlenecks suggested that basal breeds have little or no genetic connections to their ancestral populations and that their genetic distinctiveness does not signify ancient heritage. They are distinctive from the modern breeds because the genetic heritage of the modern breeds has become blurred due to admixture, and the basal breeds have mostly avoided admixture with them due to geographic or cultural barriers.[9]

Medical research

As dogs are a subspecies but their breeds are distinct genetic units, and because only certain breeds share the same type of cancers as humans, the differences in the genes of different breeds may be useful in human medical research.[10]

Breeds

Further information: Dog breeding

Pure breeds

Kennel clubs

Four varieties of the Belgian Shepherd are recognised as separate breeds by the New Zealand Kennel Club

Groups of owners that have dogs of the same breed and have an interest in dog breeding can form national Kennel clubs. Kennel Clubs maintain breed standards, record pedigrees in a breed registry (or studbook), and issue the rules for conformation dog shows and trials and accreditation of judges. They often serve as registries, which are lists of adult purebred dogs and lists of litters of puppies born to purebred parents.

A dog breed is represented by a sufficient number of individuals to stably transfer its specific characteristics over generations. Dogs of same breed have similar characteristics of appearance and behavior, primarily because they come from a select set of ancestors who had the same characteristics.[11] Dogs of a specific breed breed true, produce young that are very similar to their parents. An individual dog is identified as a member of a breed through proof of ancestry, using genetic analysis or written records of ancestry. Without such proof, identification of a specific breed is not reliable.[12] Such records, called stud books, may be maintained by individuals, clubs, or other organizations.

Kennel clubs provide the recognition of distinct dog breeds, but there are many independent clubs with differing, and sometime inconsistent standards and they need not apply scientific standards. Four varieties of the Belgian Shepherd Dog are recognised as four distinct breeds by the New Zealand Kennel Club.[13] Further, some groups of dogs which clearly share a persistent set of characteristics and documented descent from a known foundation stock may still not be recognized by some clubs as breeds. For instance, the feist is a hunting dog raised in the Southern United States for hunting small game. Feists have a consistent set of characteristics that reliably differentiate them from other dog types and breeds. However, the United Kennel Club recognizes one breed of feist, the Treeing Feist, while the American Kennel Club does not recognize any feist breed.

A dog is said to be purebred if their parents were purebred and if the dog meets the standards of the breed. Purebred dog breeders of today "have inherited a breeding paradigm that is, at the very least, a bit anachronistic in light of modern genetic knowledge, and that first arose out of a pretty blatant misinterpretation of Darwin and an enthusiasm for social theories that have long been discredited as scientifically insupportable and morally questionable."[14] Morally questionable policies regarding purity of breed include obligatory surgical procedures to spay or neuter animals in numerous contexts. The American Kennel Club, for instance, allows mixed-breed dogs to be shown but requires these animals to be altered. It doesn't make such requirements for purebred dogs. California Assembly Act AB 1634 was a bill introduced in 2007 that would require all non-working dogs of mixed breed over the age of 6 months to be neutered or spayed.[15] The bill was morally controversial, leading the American Kennel Club to fight the bill.[16]

The Canadian department of agriculture has strict standards for the documenting of what it calls "emerging breeds".[17]

Breed standards

The breed standard for each breed of dog is distinct, giving a detailed "word picture"[18] of the appearance and behaviour of an idealized dog of that breed. Included in the breed standard description are externally observable aspects of appearance and behaviour that are considered by the breed club to be the most important for the breed, and externally observable details of appearance or temperament that are considered by the breed club to be unacceptable (called faults). In addition most breed standards include an historical section, describing the place of origin and the original work done by the breed or its ancestor types.

Major registries

Dogs with a breed standard may be accepted into one or more of the major registries (kennel clubs) of dog breeds includes the Fédération Cynologique Internationale (covering 84 countries), The Kennel Club (UK), the Canadian Kennel Club, the American Kennel Club, the United Kennel Clubs International, the Australian National Kennel Council the New Zealand Kennel Club, and other national registries. The registry places the breed into the appropriate category, called a group. Some Groups may be further subdivided by some registries.

List of pure breeds

The Fédération Cynologique Internationale recognizes over 400 dog breeds.

Refer: List of dog breeds

Cross-breeds

Main article: dog crossbreed

A dog crossbreed is the result of mating two different breeds.[19]

Mixed-breeds

Main article: Mixed breed dog

A mixed breed is the result of mating different breeds.[20] A mixed-breed, mutt or mongrel is a dog that is not the result of artificial selection.[21]

Natural breeds

Natural breeds arose through time in response to a particular environment and in isolation from other populations of the species.[22] This environment included humans but with little or no selective breeding by humans.[23]

See further: Landraces

Groups of dogs mistaken for breeds

Dog types are broad categories of dogs based on form, function or style of work, lineage, or appearance. In contrast, modern dog breeds are particular breed standards, sharing a common set of heritable characteristics, determined by the kennel club that recognizes the breed. Examples include the huntaway and other livestock dogs of New Zealand, the feist dogs of the southern United States, and the Patagonian sheepdogs of Argentina, which are collies mixed with other working dogs.[24]

Further information: Dog type

List

Images

See also

References

  1. ↑ Irion, D (2003). "Analysis of Genetic Variation in 28 Dog Breed Populations With 100 Microsatellite Markers". Journal of Heredity 94 (1): 81–7. doi:10.1093/jhered/esg004. PMID 12692167.
  2. ↑ Clutton-Brock, J., 1995. Origins of the dog: domestication and early history. In:Serpell, J. (Ed.), The Domestic Dog, its Evolution, Behaviour and Interactions with People. Cambridge University Press, Cambridge, pp. 7-20
  3. 1 2 Wilcox, Bonnie; Walkowicz, Chris (March 1995). Atlas of Dog Breeds of the World (Print) (5th ed.). Neptune City, NJ Lanham, MD: TFH Publications, Inc. p. 912. ISBN 0793812844.
  4. 1 2 3 American Kennel Club (2006). Complete Dog Book. Ballantine Books; 20 edition. ISBN 0345476263.
  5. ↑ Clark, Annie Rodgers; Brace, Andrew H. (1995). The International Encyclopedia of Dogs. New York: Howell Book House. p. 8. ISBN 0-87605-624-9. In the strictest sense, dog breeds date back only to the last couple of decades of the nineteenth century, or to more recent decades in this (the twentieth) century but distinct types of dogs have existed centuries earlier.
  6. 1 2 Parker, H. G.; Kim, L. V.; Sutter, N. B.; Carlson, S; Lorentzen, T. D.; Malek, T. B.; Johnson, G. S.; Defrance, H. B.; Ostrander, E. A.; Kruglyak, L (2004). "Genetic Structure of the Purebred Domestic Dog". Science 304 (5674): 1160–4. Bibcode:2004Sci...304.1160P. doi:10.1126/science.1097406. PMID 15155949.
  7. ↑ American Kennel Club. "Dog breed groups".
  8. 1 2 3 vonHoldt, Bridgett; Lohmueller, Kirk E.; Han, Eunjung; Parker, Heidi G.; Quignon, Pascale; Degenhardt, Jeremiah D.; Boyko, Adam R.; Earl, Dent A.; Auton, Adam; Reynolds, Andy; Bryc, Kasia; Brisbin, Abra; Knowles, James C.; Mosher, Dana S.; Spady, Tyrone C.; Elkahloun, Abdel; Geffen, Eli; Pilot, Malgorzata; Jedrzejewski, Wlodzimierz; Greco, Claudia; Randi, Ettore; Bannasch, Danika; Wilton, Alan; Shearman, Jeremy; Musiani, Marco; Cargill, Michelle; Jones, Paul G.; Qian, Zuwei; et al. (2010-03-17). "Genome-wide SNP and haplotype analyses reveal a rich history underlying dog domestication". Nature 464 (7290): 898–902. Bibcode:2010Natur.464..898V. doi:10.1038/nature08837. PMC 3494089. PMID 20237475.
  9. ↑ Larson, G (2012). "Rethinking dog domestication by integrating genetics, archeology, and biogeography". doi:10.1073/pnas.1203005109.
  10. ↑ Cadieu, Edouard; Ostrander, Elaine A. (2007). "Canine Genetics Offers New Mechanisms for the Study of Human Cancer". Cancer Epidemiology Biomarkers & Prevention 16 (11): 2181–2183. doi:10.1158/1055-9965.EPI-07-2667.
  11. ↑ Donna L. Morden; Seranne, Ann; Wendell J. Sammet; Gasow, Julia (2004). The joy of breeding your own show dog. New York, N.Y: Howell Book House. ISBN 0-7645-7302-0.
  12. ↑ Lynn Marmer (1984). "The New Breed Of Municipal Dog Control Laws:Are They Constitutional?". first published in the University of Cincinnati Law Review. Archived from the original on 2000-09-26. Retrieved 13 December 2013. The court found it was impossible to identify the breed of an unregistered dog.
  13. ↑ "Standards of the Breeds: Group 5 – Working" (PDF). New Zealand Kennel Club.
  14. ↑ Budiansky", Stephen (2000). The Truth About Dogs; an Inquiry into the Ancestry, Social Conventions, Mental Habits, and Moral Fiber of Canis familiaris. New York, U.S.A.: Viking Penguin. p. 35. ISBN 0-670-89272-6.
  15. ↑ http://info.sen.ca.gov/pub/07-08/bill/asm/ab_1601-1650/ab_1634_bill_20070531_amended_asm_v94.html
  16. ↑ http://www.akc.org/canine_legislation/CA_action_center.cfm
  17. ↑ "Animal Pedigree Act 1985". Department of Justice, Canada. Retrieved 9 April 2008.
  18. ↑ American Kennel Club Glossary
  19. ↑ "cross-breed". Oxford Dictionaries. Oxford University Press. 2014.
  20. ↑ "mixed-breed". Oxford Dictionaries. Oxford University Press. 2014.
  21. ↑ Morris, Desmond (2008). "Feral dogs". Dogs: The Ultimate Dictionary of over 1,000 Dog Breeds (First Paperback ed.). Vermont: Tralfalgar Square. pp. 696–697. ISBN 978-1-57076-410-3. The mongrel is not a true breed, but it is certainly a common category of domestic dog
  22. ↑ Sponenberg, D. Phillip (May 18, 2000). "Genetic Resources and Their Conservation". In Bowling, Ann T.; Ruvinsky, Anatoly. The Genetics of the Horse. Wallingford, Oxfordshire, UK: CABI Publishing. pp. 392–393. ISBN 0-85199-429-6. Retrieved September 28, 2014.
  23. ↑ Coppinger, Raymond & Lorna Coppinger. Dogs. Scribner 2001, ISBN 0-684-85530-5, Chapter 3, "Natural Breeds", p. 85. "Natural breeds can arise locally with no human interaction"
  24. ↑ Rorem, Linda. "Herding Dog Breeds - Stockdog breeds". Herding on the Web. Retrieved 13 December 2013.

Further reading

External links

This article is issued from Wikipedia - version of the Monday, February 01, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.