The reason the earth can support a population of 850 million "village dogs" is because human beings have — inadvertently — provided them with a niche. This niche is an environment in which dogs have survived for centuries. If humans were to disappear, the village dog niche would disappear, and dogs would go extinct. Dogs could not take up residence in the wild because that niche is already taken — by wolves, coyotes, and jackals.
The reason a populace of 850 million village dogs can be supported on earth is because humans unintentionally created a niche for them. Dogs have survived in this niche for centuries. If humans became extinct, the village dog's niche would vanish, and dogs would become extinct. Dogs could not survive in the wild because coyotes, jackals, and wolves already occupy that niche (Coppinger and Coppinger 43).
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