The idea that dog breeds are an important element in defining the “personality” of pets has just taken a serious hit, thanks to genomics. The largest study ever done trying to correlate dogs’ temperaments with their DNA revealed that only 9% of the behavioral variation among dogs can be attributed to the breed to which they belong. That is, animals are, first of all, individuals as unique as their owners.
This is even true of characteristics that tend to stigmatize certain races, such as a supposed tendency to aggressiveness, say the American researchers who coordinated the study. Published in this week’s issue of the specialized journal Science, the work was based on behavioral data obtained from the owners of 18,000 dogs (mostly in the US) and on the analysis of the DNA of a subset of this group, with just over 2,000 animals ( both “race” and mestizos and mutts).
“I had never owned a dog in my life when I entered graduate school and started studying the genetics behind compulsive behaviors in dogs, with the aim of using them as models to understand equivalent problems in humans,” said Elinor Karlsson. , coordinator of the work and researcher at the University of Massachusetts, in an online press conference.
“The problem is that my research started to get stuck, in part because our sample had so few dogs. And then I noticed a funny thing. Every time someone asked me what I worked with and I started to explain, the person immediately would show me a picture of her dog and start telling me all about the animal’s behavior. That’s when it became obvious: this was the data we needed.”
The snap led to the creation of the website Darwin’s Ark, or “Darwin’s Ark”, in which the team began to provide detailed questionnaires about canine behavior (you can still participate online, and now those who fill out the questions already receive a preliminary analysis of their animal).
The questions subdivide the animals’ behavior into eight main axes (see infographic), such as sociability, obedience, seeking contact with the owner, etc. It was through Darwin’s Ark that the team also recruited the animals that were included in the genomic evaluation, which basically employed the same methods used in the search for the association between genes and certain diseases in humans.
The work revealed a relatively small association between behavioral traits and race. For the team’s expert in canine evolution, Kathryn Lord, the explanation is simple. What happens is that the clearly defined breeds we know today, following strict standards of physical appearance and (supposedly) temperament, are a recent invention, stemming from the mid-19th century onwards.
Before that, the process of selecting the characteristics of the animals was much more passive and indirect. “First, some wolves who became ancestors of dogs needed to lose their fear of contact with humans and became more docile to live close to people,” she says. “Over the millennia, some animals were selected not by constant crossbreeding, but perhaps by being better treated, given more food, etc.”
In short, says Karlsson, the most important processes for the evolution of dogs are still by far the oldest and simplest. Selecting behaviors specifically is something that takes time, and the generations that have passed since the origin of modern races would not have been enough to change that much.
The conclusion, however, does not completely rule out the association between races and certain behavioral variables. One element in which the breed seems to have greater importance is obedience, especially when the animal is being formally trained. More specifically, the habit of howling (not just barking) has a clearer genetic association with certain breeds, such as Siberian huskies and beagles (the breed of the famous Snoopy).
The study did not directly assess aggressiveness, but a broader measure called the “agonistic threshold.” “It refers to the level of stimulation that makes the animal react to something threatening, frightening or bothersome,” explains Lord. The work revealed that this measure is poorly heritable, that is, the variation between dogs has little to do with genetics.
