Why (Domesticated) Pigs are Pink

According to a recent article reporting on the work of geneticist Greger Larson, pigs developed their bright coat colors after domestication. When you think about it, this is really a no-brainer, as the coats of wild pigs and boar provide camouflage in the forest, and humans are the ones that created "breeds" that reflected what looked good to them over the long process of domestication. Accordingly, as Larson notes, the brightly colored coats reflect "the real human penchant for novelty." 

The study does reveal in detail the mechanism for changes to coat color: mutations to the gene melanocortin receptor-1 (MC1R). These mutations account for pigs that are black, or pink, or spotted, all colors and patterns that would have a hard time surviving in the wild. Interestingly, a pink pig doesn't produce any melanin, making pink a "default" color.

Today's picture is one of my own, of wild hogs corralled at the Ocmulgee Wild Hog Festival in Abbeville, Georgia. These suckers would be hard to spot in the woods, that's for sure. The New Scientist article summarizing work published in PL0S Genetics can be found here.

A New Study of the History of Pig Domestication

I hope everyone had a lovely Labor Day weekend (if you were in the U.S., of course, where the first Monday in September has been an official holiday and unofficial marker of the end of summer since 1894). I returned to the office and the first day of classes today to have several of my colleagues ask whether I'd seen this article in the L.A. Times. In "Pig study illuminates ancient human activity," Thomas Maugh reports the new findings of Greger Larson and his team, who previously demonstrated the independent domestication of pigs at as many as nine sites throughout the world. (You can find the BBC News report about that study here; about the new research here; about their work on the Pacific here).

As I understand it, additional mitochondrial DNA analysis led them to complicate the 'multiple origins of domestication' argument by showing how pigs domesticated in the Near East were taken to Europe by early farmers, who then domesticated their own wild boars which eventually replaced the imported animals. Migrating farmers then took the European pigs to the Near East where they pushed out the original domesticated animals. The researchers used these pigs, as Maugh put it, as "an excellent proxy for tracing human movements" to support the hypothesis that farming was introduced to Europe by migrating Near Eastern farmers between 10,000 and 6,000 years ago. According to Maugh's excellent summary of an increasingly complicated history involving archeology and genetic research, Larson and his team now want to extend this analysis to pigs in Asia to see how far these European pigs might have been taken.

In tracking down the news of this new research I discovered that Oxford University Press will be publishing a collection of essays in November entitled Pigs and Humans: 10,000 Years of Interaction. You can check out the table of contents here. It will be great to have much of the complex and interesting work on domestication synthesized, although based on today's post, there seems to be more and more discovered all the time.

Image above by J. Veitch from the BBC webpage.