thumb|upright=1.5|[[Dogs and sheep were among the first animals to be domesticated.]]
The domestication of vertebrates is the mutual relationship between vertebrate animals, including birds and mammals, and the humans who influence their care and reproduction.]]
thumb|upright=1.5|Evolution of temperatures in the postglacial period, after the [[Last Glacial Maximum, showing very low temperatures for the most part of the Younger Dryas, rapidly rising afterwards to reach the level of the warm Holocene, based on Greenland ice cores. Two thousand years later, humped zebu cattle were domesticated in what is today Baluchistan in Pakistan. In East Asia 8,000 years ago, pigs were domesticated from wild boar that were genetically different from those found in the Fertile Crescent. The horse was domesticated on the Central Asian steppe 5,500 years ago. The chicken was domesticated in Southeast Asia 4,000 years ago. The genes involved in tameness are largely unknown, so it is not known how or to what extent pleiotropy contributes to domestication syndrome. Tameness may be caused by the downregulation of fear and stress responses via reduction of the adrenal glands.
Neural crest cells (NCC) are vertebrate embryonic stem cells that function directly and indirectly during early embryogenesis to produce many tissue types.
Post-domestication gene flow
As agricultural societies migrated away from the domestication centers taking their domestic partners with them, they encountered populations of wild animals of the same or sister species. Because domestics often shared a recent common ancestor with the wild populations, they were capable of producing fertile offspring. Domestic populations were small relative to the surrounding wild populations, and repeated hybridizations between the two eventually led to the domestic population becoming more genetically divergent from its original domestic source population. (i.e. selection for tameness), and emotional processing. Some of these genes have been associated with aggression in some dog breeds, indicating their importance in both the initial domestication and then later in breed formation.
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