The relationship between man and dog has forged some 30,000 years ago. The most widely held thought is that this early relationship was between man and wolf. However, evidence suggests that it may have actually been some form of wild dog that we domesticated, not the wolf.
It is not known why this relationship between dogs and humans was forged. But, it most likely had a lot to do with man’s propensity for creating piles of garbage. It is very likely that wolves began rummaging around our trash heaps.
The friendliest and bravest wolves might have started to live with humans. Early man probably welcomed these friendly few because wolves have traits that we would have found useful. Even today, man uses the dog’s superior sense of smell and vision to find food, and, his speed to track and capture it.
Early dogs were also likely good alarm systems, warning early man if hostile strangers were approaching their camps. The wolves were likely just as happy with this new partnership. Now, they were more likely to be guaranteed an easy meal and a safe home base. So, this was likely a symbiotic and mutually beneficial living arrangement.
Read More:Origins of Dogs
The merger between man and wolf would have happened in more regions than one. And, it’s likely that man would have begun to put external pressure on their canine companions.
Humans did this in two ways: First, by keeping the wolves who exhibited the traits that they liked, such as alarm barking or flushing prey. And second, culling the wolves who exhibited unwanted behaviors such as aggression or lack of trainability.
Now, the physical and behavioral traits that man began to select for would have varied with each population. The climate they lived in and the type of hunting they preferred would have also altered preferences. With this, the wolf became domesticated. And, in all likelihood, eventually became the dog that we know / today.
While the behavior of those early wolves changed, man couldn’t change which behaviors the dogs came programmed with. We had to work with the behaviors that were already innate to the wolf.
Examples of this are: wolves can chase and they could bark, herd, and carry things in their mouths. But, the man didn’t teach the wolf to do these things. These behaviors were already innately programmed into the wolf.
However, man could select to make those traits stronger or weaker. An example would be allowing the dogs that were best at carrying to breed and cull the dogs that weren’t good at carrying and strengthen that trait.
But, what man couldn’t do, was teach the wolves to do something outside of their innate programming like building houses, for example. This is because wolves do not carry the genetics for it.
To summarize, man could strengthen and weaken certain behaviors. But, the dogs were still wolves. Albeit, with carefully selected behavior traits.
The man was also able to selectively breed their dogs for appearance. They could breed only for thick double coats. Or, they could select a particular size of a dog or a particular color.
But, they could only work with the colors and the recessive genes that the early dogs were already genetically programmed for (i.e. pink or green dogs were not possible because those colors were not already genetically there).
Now, changes in behavior and outward appearance influenced by man can happen in a very short period of time. An example of this is a Russian study on foxes titled, “Early Canid Domestication”. Also known as the Farm- Fox Experiment.
This study involved researchers who selectively bred foxes for “tameness” over a 40 year period. The researchers in this study simply selected the friendliest foxes and bred them to other friendly foxes. As such, each generation became more friendly.
By the eighth to 10th generation, the researchers began to notice physical changes in the foxes. Even though they were only selecting for friendliness. The foxes began losing pigmentation.
Some developed star-shaped white spots on their face. And others had floppy ears and even rolled tails. After 15 to 20 generations, they began to see shorter tails/legs, changes to the shape of their skull, and underbites/overbites.
Additionally, the foxes also began to reach sexual maturity much earlier than their wild counterparts. The foxes also began cycling twice a year like dogs. Interestingly, even though these foxes began cycling twice a year like dogs, they could not reproduce when they were bred in a heat that was outside of the usual time that foxes would become fertile in the wild.
Even though those changes and traits happened quickly through domestication, what did not change is the fact that they were still foxes. They sought out human companionship and acted very much like dogs. But, genetically, they were still foxes- not dogs. Their physiology was the same, their metabolic pathways were the same, their nutritional requirements were the same; they were still foxes.
Through the centuries, man has selected dogs for particular traits. But, those traits also need to be genetically present, or we cannot select for them. In selective breeding, we have the ability to make spotted dogs or dogs with floppy ears because those traits are already in the genes.
However, we cannot make pink dogs or dogs with five legs, because there are no pink or five-legged genes. We also can’t breed dogs that can drive cars. But, we can breed dogs to exaggerate their existing behaviors or traits that they’re genetically programmed for such as flushing or retrieving. Meaning, we can only work with the genes that we have.
It is important to remember this when we discuss nutrition. Because, we have to remember that genetically, the dog is still a wolf. Man cannot selectively breed dogs to become herbivores (like cows) or omnivores (like pigs). This is because dogs don’t have the same digestive tract and metabolic pathways as those other animals.
Dogs have virtually the same digestive tract and metabolic pathways that their ancestors had 30,000 years ago. And, the same one the wolf’s ancestors had millions of years ago. Additionally, because dogs completely lack the ability to breed with other animals, the dog's physiology and anatomy will fundamentally remain the same for another several million years. We just can’t change genetics to that degree, we can only manipulate existing genes and traits.
To that point, biologist Robert Wayne examined the DNA of seven dog breeds and 26 gray wolf populations from different locations around the world. He found that the genotype, or genetic identity, was identical with only one or two restriction sites.
This means that the modern dog’s entire DNA sequence differs from the wolf by only about 0.2%. Now, in comparison, the dog differs from the coyote by about 4%. Which, incidentally, is about the same percentage that separates man from chimpanzees.
Despite their appearance and diversity, dogs are still essentially wolves when you look under the hood. The expression of some of their genes and enzymes might have changed a bit. But it’s a mistake to think that the dog or the dog’s diet should be significantly different than the wolf's.