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Domestication (from the Latin ''ラテン語:domesticus'': "of the home") is the cultivating or taming of a population of organisms in order to accentuate traits that are desirable to the cultivator or tamer. The desired traits may include a particular physical appearance, behavioral characteristic, individual size, litter size, hair/fur quality or color, growth rate, fecundity, lifespan, ability to use marginal grazing resources, production of certain by-products, and many others. Domesticated organisms may become dependent on humans or human activities, since they sometimes lose their ability to survive in the wild.〔"Domestication." Dictionary.com. Based on the Random House Dictionary (Random House, Inc. 2013). http://dictionary.reference.com/browse/domesticate〕 Domestication differs from taming in that it may refer not simply to a change in organisms' behaviors or environmental socialization, but also potentially even in their phenotypical expressions and genotypes. The word ''domestication'' also is more commonly used to mean a change within whole populations, while ''taming'' is more commonly used to mean a change within individuals. Furthermore, taming typically applies only to animals and their becoming habituated to human presence, while domestication is a broader term and can include plants, fungi, and other types of organisms. Plants domesticated primarily for aesthetic enjoyment in and around the home are usually called ''house plants'' or ''ornamentals'', while those domesticated for large-scale food production are generally called ''crops''. A distinction can be made between those domesticated plants that have been deliberately altered or selected for special desirable characteristics (see cultigen) and those plants that are used for human benefit, but are essentially no different from the wild populations of the species. Animals domesticated for home companionship are usually called ''pets'', while those domesticated for food or work are called ''livestock'' or ''farm animals''. == Background == Charles Darwin was the first to describe the connection between domestication, selection and evolution. Darwin described how the process of domestication can involve both unconscious and methodical elements. Routine human interactions with animals and plants create selection pressures that cause adaptation to human presence, use or cultivation. Deliberate selective breeding has also been used to create desired changes, often after initial domestication. These two forces, unconscious natural selection and methodical selective breeding, may have both played roles in the processes of domestication throughout history.〔 Both have been described from human perspective as processes of artificial selection. The domestication of wheat provides an example. Wild wheat falls to the ground to reseed itself when ripe, but domesticated wheat stays on the stem for easier harvesting. There is evidence that this change was possible because of a random mutation that happened in the wild populations at the beginning of wheat's cultivation. Wheat with this mutation was harvested more frequently and became the seed for the next crop. Therefore, without realizing, early farmers selected for this mutation, which may otherwise have died out. The result is domesticated wheat, which relies on farmers for its own reproduction and dissemination.〔Zohary, D. & Hopf, M. (2000). ''Domestication of Plants in the Old World'' Oxford: Oxford Univ. Press.〕 Selective breeding may best explain how continuing processes of domestication often work. Evidence of the power of selective breeding comes from the Farm-Fox Experiment by the Russian scientist, Dmitri K. Belyaev, in the 1950s. His team bred the domesticated silver fox (''Vulpes vulpes'') and selected the individuals that showed the least fear of humans. Then Belyaev's team selected only those that showed the most positive response to humans. He ended up with a population of grey foxes whose behavior and appearance was significantly changed. They no longer showed any fear of humans and often wagged their tails and licked their human caretakers to show affection. These foxes had floppy ears, smaller skulls, rolled tails and other traits commonly found in dogs. Despite the success of this experiment, it appears that selective breeding cannot always achieve domestication. Attempts to domesticate many kinds of wild animals have been unsuccessful. Although the four species of zebra can interbreed with the horse and the donkey, attempts at domestication have failed.〔Clutton-Brock, J. (1981) ''Domesticated Animals from Early Times''. Austin: Univ. Texas Press. 〕 Factors such as temperament, social structure and ability to breed in captivity play a role in determining whether a species can be successfully domesticated.〔 In human history to date, only a few species of large animal have been domesticated. In approximate order of their earliest domestication these are: dog, sheep, goat, pig, ox, yak,〔Ning L., Jinge G. and Aireti. 1997. "Yak in Xinjiang", in Miller D.G., Craig S.R. and Rana G.M. (eds), ''Proceedings of a workshop on conservation and management of yak genetic diversity held at ICIMOD, Kathmandu, Nepal'', October 29–31, 1996. ICIMOD (International Centre for Integrated Mountain Development), Kathmandu, Nepal. pp. 115–122.〕 reindeer,〔Cronin, M.A.; Renecker, L; Pierson, B.J. and Patton, J.C.; "Genetic variation in domestic reindeer and wild caribou in Alaska"; ''Animal Genetics'', volume 26, Issue 6 (December 1995), pp. 427–434〕 water buffalo, horse, donkey, llama, alpaca, Bactrian camel and Arabian camel.〔Diamond, Jared; ''Guns, Germs, and Steel: The Fates of Human Societies''; p. 147. ISBN 0-393-31755-2〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Domestication」の詳細全文を読む スポンサード リンク
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