I am only …, a tracking novice, … My background is in Zoology with extensive personal and academic studies in canine evolution and behavior. Lately, I have been researching the differences between wolves and the domestic dog, including comparative anatomy and Ethology.
The first basic comment I want to address is the physical differences between dogs and wolves. They are not identical. DNA is only part of the way attributes are displayed within individuals. There are many factors in which genes are ” used” or activated. Dogs have 100% similar DNA yet they display an endless variety of different behavior and physical differences. Wolves are more similar to each other due to their environmental niche being specialized. In the natural environment “different ” is a disadvantage. Wolf DNA is more stable, shows little variety. Dog’s ecological “pressure” is man, which leads to versatility and variety. Humans value the unique, therefore dog DNA has been influenced to be less stable and more varied in phenotype.
Evolution comes from environmental change. Adaptation happens through natural pressure or human pressure intentional or unintentional. In dogs that environment is 15,000 or more years of human pressure. Human influence can result in exponentially fast changes. This would include food use changes as well as type and behavior. It is quite obvious that the domestic dog would adapt to eat human food, it’s primary source. This would include cooked meats, grains and vegetables. Cooking increases both human and canine ability to absorb nutrients. It is quite possible that the more varied diet was an advantage over the hunting raw diet of the wolf, or the domestic dog would never have evolved at all.
Eating provided food also caused physical change . Due to The lack of need to hunt, dog brains became distinctively smaller, requiring less food volume, an advantage. An adult German Shepherd’s brain is the size of a 4 month wolf pup. Very few domestic Dogs would be able to sustain themselves by hunting. This is physical and lack of full instinctive prey drive. Feral domestic dogs almost always eat garbage to survive, only supplement with occasional small animals.
Dogs do show both behavioral adaptations and physical differences from wolves in head, teeth and digestive tract. It certainly does not mean they no longer eat meat, but it does tell us they have adapted to a more human cooked type diet. I am not a digestion expert, but a single source diet can cause many problems in species. Cooked food increases ability to digest additional sources. The domestic dog is a highly successful mammal, so successful they are found ubiquitously in human company around the world They did not do this by eating ONLY meat. Fossil evidence of domestic dogs is first found about the same time humans began agricultural. Meat was a precious commodity, they did not share the best cuts with their dogs. The dog got what was left over.
IMHO, I see no reason to feed exclusively protein to my dog. A high quality, primarily meat diet with cooked supplements seems the most balanced from a zoological view. I share the concerns with grain based or chemical additives though. Nutrition is not my specialty, but I know dogs are not wolves and I don’t believe we need to feed them the same. I don’t get into a ” raw” diet debate. I just do what my knowledge base tells me. I have friends with healthy, long lived dogs who feed raw and many who feed commercial with old dogs. I have lost many dogs at 16 years On commercial food. my two cancer dogs had a genetic component. I put a kidney failure dog on raw and it changed nothing. There are just too many factors to make conclusions on anecdotal experience.