Do not judge a book by its cover. Don’t judge a dog by its breed.
After conducting owner studies for 18,385 dogs and sequencing the genomes of 2,155 dogs, a group of researchers reported a variety of findings Thursday in the journal Science, including that for predicting some dog behaviors, breed is essentially useless, and for the most, not very good. For example, one of the clearest findings in the large multi-faceted study is that breed has no discernible effect on a dog’s reactions to something it finds new or strange.
This behavior is related to what the non-scientist might call aggression and seems to cast doubt on breed stereotypes of aggressive dogs, such as pit bulls. One thing that pit bulls did score highly on was human sociability, no surprise to anyone who has seen internet videos of lap-loving pit bulls. On the other hand, Labrador retriever ancestry did not appear to have a significant correlation with human sociability.
This is not to say that there are no differences between races, or that race cannot predict some things. If you adopt a border collie, said Elinor Karlsson of the Broad Institute and the University of Massachusetts Chan Medical School, an expert in canine genomics and an author of the report, chances are it will be easier to train and be interested in toys.” is going to be higher than if you adopt a Great Pyrenees.”
But for a particular dog you just don’t know — on average, breed is responsible for only about 9 percent of the variations in a particular dog’s behavior. And no behavior was limited to one breed, not even howling, although the study found that behavior was more strongly associated with breeds such as Siberian huskies than with other dogs.
And yet, in what seems paradoxical at first, the researchers also found that patterns of behavior are highly inherited. The behavior they studied had a 25 percent heritability, a complex measure that indicates the influence of genes, but depends on the group of animals studied. But with enough dogs, heredity is a good measure of what is inherited. When comparing whole genomes, they found several genes that clearly influence behavior, including one for how friendly dogs are.
What the study means is that dog behavior is highly inherited, but the genes that determine whether your dog is friendly, aggressive or aloof date back to way before the 1800s when most modern breeds, such as those recognized by the American Kennel Club , were created . Breeding has been primarily for physical traits ever since.
Kathryn Lord, an evolutionary biologist also at the Broad Institute and the University of Massachusetts Chan Medical School, and another author of the paper, said, “German Shorthaired Pointers were slightly more likely to point or Golden Retrievers were slightly more likely to fetch.” or Siberian huskies to howl.”
But beware of buyer or dog adoption. “I know Labradors that howled and Papillons that orphaned and greyhounds that retrieved and retrievers that didn’t,” said Dr. Lord.
The findings probably won’t come as a surprise to people who work closely with dogs, such as Dr. Cynthia Otto, director of the Penn Vet Working Dog Center at the University of Pennsylvania. dr. Otto, who was not involved with the report, said the study “makes perfect sense to me. I think there are some general behavioral traits that are more common in some breeds than others, but the individual variation is so great within a breed.” .”
For example, she said breeders have favored border collies that are easier to train, which may explain why it is easier to train them. But she added that “certainly within border collies — there’s still great individual variation.”
The research for the new study began about eight years ago, said Dr. Karlsson, and the original goal was to compare mutts with purebred dogs in what’s called a genome-wide association study, to look for regions of DNA or genes associated with certain behaviors.
Kathleen Morrill, also an author of the paper at the Broad Institute and Chan Medical School, said the sheer number of mixed-breed dogs, or what the authors and you might call mutts, was a great strength.
“Mutts were actually the perfect kind of dog to explore the links between breed and behavior,” she said, because their DNA is so shuffled that it’s easier to separate looks from behavior.
Evan Maclean, the director of the Arizona Canine Cognition Center at the University of Arizona who was not involved in the study, said, “This is one of the first papers that has done really impressive work in canine genomics with mixed-breed dogs.” .” These dogs have such variety that it makes genetic comparisons more powerful, he said, but they’ve been excluded from many previous studies. “And this paper just shows how valuable those populations can be,” he added.
The researchers found 11 specific regions of DNA linked to behavior. This finding could help the study of human genomics, although the researchers are just scratching the surface of the relationship between the genomes of both species. For example, a region that affected the likelihood of a dog howling is associated with language development in humans. And a region associated with enjoying those around them is also present in human DNA, where it is associated with long-term memory.
Contrary to most scientific studies, any dog owner can help with this project.
The researchers got their wealth of information from Darwin’s Ark, a project Dr. Karlsson and her colleagues set up by asking owners of any breed or mutt to submit DNA swabs from their dogs and answer questionnaires. They are still looking for more dogs.
“Anyone from anywhere in the world can apply,” said Dr. Karlsson.