抄録
Compared to their wild ancestors, domesticated animals have evolved not only through natural selection. During the long period of their domestication, artificial selection by humans has been directed toward changes in form, shape, coloration, physiological function, etc. The domesticated chicken, Gallus gallus domesticus, is considered to have been derived from its wild ancestor, the Red Junglefowl Gallus gallus, for the purpose of exploitation. For example, different cultures selected characters and behaviours for certain purposes, such as crowing to signal the time, cockfighting, divination and food consumption. Additionally, in many parts of Asia, the coloration of the plumage and shank can be important elements for use in ritual ceremonies. Clearly, cultural background may influence the external and internal features of the domesticated chicken. To elucidate the domestication process, we investigated the influence of cultural-specific background, value system, preference and knowledge on human evaluation of the shape and colour of chickens. We compared two distinct cultures, represented by Chiang Rai Province, Thailand and Okinawa Prefecture, Japan. An optimal solution model revealed clear differences between the subjects of Thailand and Japan in their respective preference for chicken figures. We also used a five-stage evaluation to investigate the tendency that people evaluate a chicken figure as “for meat” or “for cockfighting”, as well as “for appreciation” or “for economy”. The study demonstrated that the differences observed in the evaluation results related to cockfighting were reflected also in a contrast in breeding knowledge.
