Characteristics
Domestic pigs are easily recognized by their long snouts, large heads and small tails, which curl around or feature a kink. Pigs possess four toes per foot and use the middle two to walk. The color of domestic pigs varies according to their breed and age; many are a shade of brown or black, becoming grayer as they get older, but others are white or pink in color. Domestic pigs have coarse hair that covers their bodies.
Origins
The domestic pig found in the 21st century is a distant relative of the Eurasian wild boar. According to the article "The origin of the domestic pig: independent domestication and subsequent introgression," domestic pigs had already diverged from wild boar into a separate subspecies before human domestication occurred; this divergence happened some 500,000 years ago. Mankind began to domesticate pigs for meat and other uses some 9,000 years ago.
Range
The domestic pig is widely spread around the world. It is perhaps most common in parts of Europe and Asia, but can also be found in the Middle East and North America for example. The domestic pig was introduced to North America by Spanish explorers.
How They Live
Some domestic pigs are kept as pets, but these animals are typically found on farms, living in a well-fenced compound during the day, and a pig house at night. Such houses are generally built from bricks and concrete, durable materials that not only provide adequate shelter for the pig but are also strong enough to withstand a pig's escape attempts. Pigs are often associated with mud and thus dirt, but in fact pigs enjoy a clean habitat, and so owners must ensure that pig living areas are looked after. Pigs only sit in mud to cool down, since they can't naturally perspire.
Uses
Domestic pigs are commonly used to produce meat, and humans obtain bacon, ham and sausages from these animals. Pigs have been slaughtered for the purpose of food since they were first domesticated many centuries ago. Pigs are also used in the production of leather. In terms of scientific study, the domestic pig is a useful animal, since it allows experts to study the process of evolution when comparing the domestic pig to its wild boar ancestor.