Are pigs all pink?
Peppa Pig Graffiti, by duncan C via flickr
Honey, by Thomas Hawk vic flickr
Peppa pig and Piglet from Winnie the pooh are two of the most famous cartoon pig character around the world. These cute cartoon piggies catch everyone’s eyes. But have you ever wondered why cartoon pigs are pink?
In reality, only a small proportion of domestic pigs are pink. Most of them are black or yellow. While wild hogs are rarely found to be pink. They are generally in black or other dark colour and covered by sharp short fur. So where exactly are the pinky piggies coming from?
History of pig domestication
Traceback to 13,000 B.C, when wild hogs were domesticated, most of the domestic pigs remain the colour of black and covered with thick fur. During many years of reproduction, some genes are changed, causing the black pigment (eumelanin and pheomelanin) in pigs lose their function. This mutation (change in gene and lost function of pigments) results in the pink or white pig. Mutation to the black pigment is quite common among pigs. But pink or white pigs are mostly found in domestic pigs rather than wild hogs. Why pink wild hogs were eliminated while domestic pigs remain pink?
The power of nature
Wild hogs are great predators. They are the expert of hiding and hunting. The black fur gives them the world finest camouflage to hide in the bushes. However, once the mutation happened, they lose the ability to hide because the pink colour is too obvious in the wild while everyone else is either green, black or other dark colours. Hence, pink wild hogs can hardly hunt other animals for food. In addition, lions, tigers or any other predators who eat hogs can easily spot pink hogs. Hence, most of the pink hogs cannot live long enough to reproduce and pass this pink gene down to their offspring. The mutated gene is eliminated quickly in the species. This selection of gene is called natural selection which only the fittest characteristics can be passed down.
The power of human
Domestic pigs, however, does not need to hunt or survive in the wild. The only factor deciding if certain genes can pass down is human. Breeders tend to keep the pigs with better characteristics such as high lean meat proportion or fast-growing. They tend to use these “good” pigs to breed, hence increase the chance of keeping these genes. But why farmers decided to keep the pink gene? Scientists have pointed out that the original idea of keeping pink pigs is to distinguish between domestic pigs and wild hogs. In addition, the mutation of black pigment won’t bring any bad effects except the change of appearance. Psychologists also mentioned that this selection might happen because farmers tend to keep the rare colour to show off. In this case, the selection is referred to as selective breeding.
From here, we can feel the strong power from different selections and distinctive outcomes from identical ancestors. And of course, the answer to our question is, not all the pigs are pink. Probably the reason why so many pinky piggies characters are created is simply because they look cute.
For some extra information about natural selection and selective breeding, check out this fantastic BBC post.