“Wolf DNA” lurks in many modern dog breeds

At the genome-wide level, canines and wolves are clearly separated. However, when the research team built phylogenetic trees for each of the 1,582 genes, they found that no single gene supported canine monogamy. Further examination of mitochondrial DNA and phylogenetic trees for the Y chromosome revealed a complex interaction between dog and wolf subspecies. This discrepancy is evidence of multiple rounds of gene transfer in the past.

Imprints on physical fitness and personality

The researchers found that wolf genes are associated with a variety of canine traits, most notably body size. Larger dogs tend to have more wolf ancestry, and some working breeds, such as Arctic sled dogs, wild dog breeds, and hunting dogs, are more likely to have this trait. On the other hand, terriers, bird dogs and scenthounds were less affected by wolf genes.

It is worth noting that among large service dogs, the influence of wolf ancestry varies greatly between breeds. The Sarabi, Central Asian Shepherd Dog, and Anatolian Shepherd Dog, livestock guarding dogs from Turkey and Central Asia, inherited 0.5-1.2 percent of their genes from wolf ancestors, while Neapolitan Mastiffs, Bull Mastiffs, and Saint Bernards showed almost no trace of wolf lineage.

On the other hand, even the Chihuahua, the smallest dog breed in the world, has been found to have a small percentage of wolf ancestry, about 0.2 percent. These differences speak of the historical specificity of the development of the breed.

The personalities of dog breeds also showed striking patterns depending on the proportion of wolf genes they had. When compared to breed-specific personalities described by the Kennel Club, the organization responsible for certifying dog breeds, breeds with fewer wolf genes were more likely to be described as “friendly,” “obedient,” “easy to train,” and “affectionate.”

In contrast, breeds with strong wolf ancestry tend to be described as “suspicious of strangers,” “independent,” “wary,” and “territorial.” However, researchers cautioned that these descriptions are based on subjective human observations, and it is unclear whether wolf DNA is directly related.

Adaptive genes that support survival

Wolf-derived genes are not just leftovers from evolution, but may actually contribute to canine survival. When gene analysis was performed on regions of the village dog genome that were enriched in wolf ancestral elements, the only significant functional category was the olfactory transduction pathway. This finding suggests that gene flow from wolves may have enhanced the village dog’s sense of smell, thus improving its ability to scavenge human food waste.

Village dogs that are not directly cared for by humans generally have a very low survival rate. For stray dogs in urban environments, the survival rate at five months is less than 37 percent, with some reports as low as 16 percent. Their keen sense of smell may play a major role in their survival in these harsh environments.