When Mal Nesheim and I were writing our book about the pet food industry, Feed Your Pet Right, we were constantly challenged to defend our contention that dogs can eat pretty much anything, including commercial food products made with grains.
Our reasoning: dogs are not wolves. They evolved to take full advantage of the leftovers from human food consumption.
Now a study published in Nature Magazine, “The genomic signature of dog domestication reveals adaptation to a starch-rich diet,” explains how this happened.
The investigators sequenced the entire genomes of dogs and wolves. They identified 3.8 million genetic variants, and used them to identify 36 genomic regions that appeared related to dog domestication. Many of these gene regions appear to be associated with the behavioral changes needed to domesticate wolves.
Ten of the genes turned out to have roles in starch digestion; three of these genes promote digestion.
The investigators identified mutations in key wolf genes that allowed this to happen. The study provides evidence that dogs “thrive on a diet rich in starch, relative to the carnivorous diet of wolves.”
This, they say, constitutes a crucial step in the early domestication of dogs.
In conclusion, we have presented evidence that dog domestication was accompanied by selection at three genes with key roles in starch digestion: AMY2B, MGAM and SGLT1. Our results show that adaptations that allowed the early ancestors of modern dogs to thrive on a diet rich in starch, relative to the carnivorous diet of wolves, constituted a crucial step in early dog domestication…In light of previous results describing the timing and location of dog domestication, our findings may suggest that the development of agriculture catalysed the domestication of dogs.
If your dog is domesticated, it will love those carbs just as you do. But keep it away from the pizza and cookies. We seem to have co-evolved to put on the pounds together too.