User:Fowler&fowler/Chicken

Two questions are considered here: (a) which is the original domesticated breed (in poultry farming terms) that produced the breeds that are eaten around the world, and (b) which is the ancestral progenitor(s) (in phylogeographic terms) – in the wild – of all the breeds.

• For (a), the answer is provided in the signed article in Britannica by Garrigus, W. P. (2007) "Poultry Farming". Encyclopædia Britannica. Quote: "Humans first domesticated chickens of Indian origin for the purpose of cockfighting in Asia, Africa, and Europe. Very little formal attention was given to egg or meat production... The breeds of chickens are generally classified as American, Mediterranean, English, and Asiatic... The only Asiatic breed of significance today, the Brahma, which originated in India, has three varieties, the light Brahma being preferred because of its size." In addition, archaeological evidence has traditionally conferred the "first to domesticate" status on the Indus Valley Civilization. (See: Zeuner, F.E., 1963. A History of Domesticated Animals. Harper and Row, New York, pp. 443–455.) Recently, it has been claimed (based on paleoclimatic assumptions) that chickens were domesticated in Southern China in 6000 BC, but no hard evidence has been provided to date. (See: West, B., Zhou, B.X., 1988. "Did chickens go north? New evidence for domestication." J. Archaeol. Sci. 14, 515–533. This has been referred to by the latest reference I could find: (Al-Nasser, A. et al (June 2007) "Overview of chicken taxonomy and domestication." World's Poultry Science Journal 63: 285-300.), who say, "Archaeological evidence in China indicate that chickens had been domesticated by 5400 BC, but it is not known whether these birds made much contribution to the modern domestic fowl. Chickens from the Harappan culture of the Indus Valley (2500-2100 BC) may have been the main source of diffusion throughout the world."
• For (b), there have been a lot of developments in the last ten years. First, all "Thailand origin" references are based on the paper Fumihito et al. (1996) "Monophyletic origin and unique dispersal patterns of domestic fowls," Proc. Natl. Acad. Sci. USA Vol. 93, pp. 6792-6795, June 1996. However, this study was discovered to be flawed later, since its phylogenetic analysis was based on incomplete data. Recent studies point to multiple maternal origin, however, with the clade found in the Americas, Europe, Middle East, and Africa, originating from the Indian subcontinent, where a large number of unique haplotypes occur. (See: Liu, Y-P et al. (2006) "Multiple maternal origins of chickens: Out of the Asian jungles," Molecular Phylogenetics and Evolution, Volume 38, Issue 1, January 2006, Pages 12-19. See also, Zeder et al (2006) "Documenting domestication: the intersection of genetics and archaeology," Trends in Genetics, vol 22, number 3, pp. 139-155.