Originally Posted by
hutash
To the OP, yes humans did create cows by selective breeding and domestication. Likely from a wild auroch like bovid. as they have done with sheep, goats
, pigeons, pigs and a host of other species.
While the current hypothesis on dog domestication is as Leroy discribes, it is mostly speculation, and probably only partly true. Humans managed to domesticate dozens of species with the "hanging around humans" effect. It is just as likely dogs were domesticated as a food source, but found to have other useful purposes.