i'm curious, and the wikipedia articles for domestic pigs or feral pigs don't seem to make any reference to this. if this is actually real, what's the mechanism for this change? the only thing i can think of that would make sense would be that it's dietary, but the pigs at the farm up the hill from me spend most of their time foraging around their very large enclosure, and they still seem pretty tusk-less and stereotypically pink as any domestic pig.