Today's purebreds only appeared in the 1800s as a result of genetic manipulation.
Is a pit bull more aggressive? And is a bulldog necessarily calm and gentle? These preconceptions about dog behavior die hard. Yet analysis of thousands of canine genomes, coupled with observations from owners, shows that a dog's breed alone cannot determine its behavior.
In their work, researchers Elinor Karlsson and Kathleen Yates of the Broad Institute at MIT (Massachusetts Institute of Technology) used genome-wide association studies to search for common genetic variations that may predict individual behavioral traits in 2155 dogs of pure and mixed breeds.
They then combined this information with the 18,385 responses listed in an open database (Darwin's Ark) devoted to canine behaviors reported by their owners.
The results of these analyses, which included data from 78 breeds, identified 11 variations in DNA sequences strongly associated with behaviors, but none of them was race-specific.
Our results invalidate the hypothesis according to which certain breeds are more aggressive, more obedient or more affectionate than others, note in a press release the authors of this work, the details of which are published in the journal Science (in English).
This research confirms the conclusions of a meta-analysis published in 2015 of four decades of studies devoted to the heritability of behavioral traits of dog breeds.
All the studies on the subject say the same thing. This is the most comprehensive and complex conducted on the issue to date, says Dr. David Silversides, professor at the Faculty of Veterinary Medicine at the University of Montreal.
This work also showed that the behavioral characteristics attributed to modern breeds are influenced by several genes, as well as by the environment, and are found, to varying degrees, in all breeds.
- The genetic heritage of the domestic dog (Canis lupus familiaris) was fully deciphered in 2005.
- It has made it possible to establish genetic similarities with humans, but also particular differences between the various dog breeds.
- Dogs have approximately 19,300 genes.
A study published in Nature Communications (in English) in 2017 showed that the domestication of the dog would have taken place between 20,000 and 40,000 years before our era from the same population of wolves (domesticated?).
< p class="e-p">Initially, dogs were probably selected for very specific functions such as hunting game or herding animals.
The majority of behaviors that we consider to be characteristics of certain modern dog breeds are most likely the result of thousands of years of evolution, from wolves to wild dogs, then to domesticated dogs, and finally to modern breeds. , notes Elinor Karlsson.
Current purebreds only appeared in the 1800s as a result of genetic manipulations whose objective was to meet a physical ideal and to keep the lineage purity.
Current breeds are assigned temperaments and behaviors based on the estimated function of their ancestral population. By extension, a dog's breed ancestry is presumed to predict its temperament and behavior, the authors argue.
This popular assumption has led some municipalities to pass laws banning certain breeds following high-profile incidents involving aggressive dogs.
Dr Silversides believes these bans often miss the mark because they are not based on science. We are always looking for simple solutions, he says. We're not saying that genetics isn't involved, but with current techniques [for complex phenotypes like behaviors], we can't really identify a region in the genome responsible for a behavior, explains Professor Silversides.
“A rapid test [as for COVID] would be the solution! But there are no quick tests to assess dog genetics.
In contrast, the environmental and social factors that contribute to good (and bad) dog behavior are well known. For example, a lack of socialization of the dog can cause problems in the presence of other animals or strangers. He can become stressed, anxious, but also aggressive.
An individual behavioral assessment of a dog must be carried out to find out if he is exhibiting problematic behavior. And owners also need to be educated, because bad behavior is not race-related, says Dr. Silversides.
The Order of Veterinary Physicians of Quebec offers training for its members to improve their knowledge in their assessment of canine dangerousness which is increasingly requested by municipalities and which must be carried out by a veterinarian.