Four lage hen

                                            Four lage hen

The domestic chicken is descended primarily from the red junglefowl (Gallus gallus) and is scientifically classified as the same species.[21] As such it can and does freely interbreed with populations of red jungle fowl.[21] Recent genetic analysis has revealed that at least the gene for yellow skin was incorporated into domestic birds through hybridization with the grey junglefowl (G. sonneratii).[22] The traditional poultry farming view is that chickens were first domesticated for cockfighting in Asia, Africa, and Europe, rather than for egg or meat production. In the last decade there have been a number of genetic studies to clarify the origins. According to one study, a single domestication event occurring in the region of modern Thailand created the modern chicken with minor transitions separating the modern breeds.[23] However, that study was later found to be based on incomplete data, and recent studies point to multiple maternal origins, 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.[24][25] It is postulated that the jungle fowl, known as the bamboo fowl in many Southeast Asian languages, is a special pheasant well adapted to take advantage of the large amounts of fruits that are produced during the end of the 50-year bamboo seeding cycle to boost its own reproduction.[26] In domesticating the chicken, humans took advantage of this prolific reproduction of the jungle fowl when exposed to large amounts of food.It has been claimed (based on paleoclimatic assumptions) that chickens were domesticated in Southern China in 6000 BC.[28] However, according to a recent study,[29] it is unclear whether those birds were the ancestors of chickens today. Instead, the origin could be the Harappan culture of the Indus Valley. Eventually, the chicken moved to the Tarim basin of central Asia. The chicken reached Europe (Romania, Turkey, Greece, Ukraine) about 3000 BC.[30] Introduction into Western Europe came far later, about the 1st millennium BC. Phoenicians spread chickens along the Mediterranean coasts, to Iberia. Breeding increased under the Roman Empire, and was reduced in the Middle Ages.[30] Middle East traces of chicken go back to a little earlier than 2000 BC, in Syria; chicken went southward only in the 1st millennium BC. The chicken reached Egypt for purposes of cock fighting about 1400 BC, and became widely bred only in Ptolemaic Egypt (about 300 BC).[30] Little is known about the chicken's introduction into Africa. Three possible routes of introduction in about the early first millennium AD could have been through the Egyptian Nile Valley, the East Africa Roman-Greek or Indian trade, or from Carthage and the Berbers, across the Sahara. The earliest known remains are from Mali, Nubia, East Coast, and South Africa and date back to the middle of the first millennium AD.[30] Domestic chicken in the Americas before Western conquest is still an ongoing discussion, but blue-egged chickens, found only in the Americas and Asia, suggest an Asian origin for early American chickens.

An unusual variety of chicken that has its origins in South America is the araucana, bred in southern Chile by the Mapuche people. Araucanas, some of which are tailless and some of which have tufts of feathers around their ears, lay blue-green eggs. It has long been suggested that they pre-date the arrival of European chickens brought by the Spanish and are evidence of pre-Columbian trans-Pacific contacts between Asian or Pacific Oceanic peoples, particularly the Polynesians, and South America. In 2007, an international team of researchers reported the results of analysis of chicken bones found on the Arauco Peninsula in south-central Chile. Radiocarbon dating suggested that the chickens were Pre-Columbian, and DNA analysis showed that they were related to prehistoric populations of chickens in Polynesia.[31] These results appeared to confirm that the chickens came from Polynesia and that there were transpacific contacts between Polynesia and South America before Columbus's arrival in the Americas.A published, apparently pre-Columbian, Chilean specimen and six pre-European Polynesian specimens also cluster with the same European/Indian subcontinental/Southeast Asian sequences, providing no support for a Polynesian introduction of chickens to South America. In contrast, sequences from two archaeological sites on Easter Island group with an uncommon haplogroup from Indonesia, Japan, and China and may represent a genetic signature of an early Polynesian dispersal. Modeling of the potential marine carbon contribution to the Chilean archaeological specimen casts further doubt on claims for pre-Columbian chickens, and definitive proof will require further analyses of ancient DNA sequences and radiocarbon and stable isotope data from archaeological excavations within both Chile and Polynesia.

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