But what about domestic pigs that escape and breed in the wild? Well, these are known as feral pigs/hogs and not boars, since, even though they live in the wild (and may have for several generations), they are not true wild boars.
So, how do domestic pigs and wild boars differ genetically and physically? Well, all swine share a common ancestor — the Eurasian wild boar or
Sus scrofa. Wild boars are of the species
Sus scrofa, whereas domestic pigs are of the subspecies
Sus scrofa domesticus. (A few taxonomists put the domestic pig in a separate species from its wild counterparts, which is known as
Sus domesticus.) Humans began domesticating pigs as early as 8000 B.C., and now there are many subspecies of
Sus scrofa throughout the world.
In regards to appearance, wild boars generally have thicker, bristlier coats than domestics and have a noticeable ridge of hair running along their backs. They also have longer, straighter tails, and longer legs and heads.
That being said, feral domestic pigs start to take on the physical characteristics of wild boars after just one or two generations of being in the wild. Once they take on this wild appearance, it is hard to distinguish them from a pure
Sus scrofa. Also, wild boars and feral pigs breed readily and create offspring that are nearly identical to wild boars, making them even more difficult to tell apart.
In truth, considering their high level of hybridization and similar appearance, there’s not much difference between feral pigs and wild boars. Even scientists have a hard time identifying these animals without analyzing them at the molecular level.
http://knowledgenuts.com/2014/08/06/...nd-wild-boars/