At the whole-genome level, canines and wolves are clearly separated. But when the research team constructed phylogenetic trees for each of the 1,582 genes, they found that not a single gene supported canine monophyly. Further examination of mitochondrial DNA and Y chromosome phylogenetic trees revealed a convoluted interaction between the dog and wolf lineages. This discrepancy is evidence of many rounds of gene transfer in the past.
Imprints on body structure and personality
Scientists have found that wolf genes are linked to various characteristics of dogs, in particular 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. Terriers, bird dogs AND tracking dogson the other hand, wolf genes had the least influence on them.
It is worth noting that among enormous service dogs, the effect of wolf ancestry varied greatly by breed. The Sarabi, the Central Asian Shepherd Dog, and the Anatolian Shepherd Dog, which are cattle guard 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 ancestry
On the other hand, even Chihuahuas, the smallest dog breed in the world, have been found to have a compact percentage of wolf ancestors, about 0.2%. These differences speak to the historical specificity of the breed’s evolution.
The personalities of dog breeds also showed striking patterns depending on the proportion of wolf genes they possessed. Compared with 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,” “willing to obey,” “easily trained” and “affectionate.”
In contrast, breeds with a powerful wolf ancestry were typically described as “suspicious of strangers”, “independent”, “cautious” and “territorial”. Scientists cautioned, however, that these descriptions are based on subjective human observations and that it is unclear whether wolf DNA is directly related to
Adaptive genes that support survival
Wolf genes are not simply a leftover from evolution, but may actually contribute to dogs’ survival. When gene ontology analysis was performed on areas of the rural dog genome that were enriched for wolf ancestral elements, the only significant functional category was the olfactory transduction pathway. This result suggests that the influx of genes from wolves may have enhanced the country dog’s sense of smell, thereby improving its ability to find human food waste.
Farm dogs that are not directly cared for by humans generally have a very low survival rate. For stray dogs living in cities, the survival rate at five months is just under 37 percent, with some reports suggesting it is as low as 16 percent. Their acute sense of smell may play a key role in their survival in these arduous conditions.