By Turning Wolves Into Dogs, Humans Changed the Animals’ Brain Structure. Illustration: petepop
According to a study, the transformation from wolves to dogs goes far beyond appearance: humans also reshaped the dogs’ brains.
To conduct this research, Erin Hecht, a neuroscientist at Harvard University, and her colleagues compiled a library of brain MRIs from 62 purebred dogs representing 33 different breeds.
When she first looked at the images side by side, “You could see the results staring back at you,” she said. The dogs, including bichon frises, Labradors, and others, displayed a variety of head shapes and sizes. But none of those traits alone explained the variation in their brain organization.
Hecht and her team identified six networks of brain regions that tended to be larger or smaller depending on the dog and that varied together. This pattern led Hecht to theorize that these regions likely work together to support different behaviors.
She wondered if the varied layouts could stem from behavioral differences between breeds. For instance, beagles can sniff out cancerous tumors in humans and alert doctors, while a border collie can herd hundreds of sheep (or even turkeys) into a pen with remarkable speed and agility.
The researchers examined how the six networks differed among dogs based on the traits for which they were bred, as defined by the American Kennel Club.
Each of the six brain networks correlated with at least one behavioral trait, the researchers reported in 2019 in the Journal of Neuroscience. For example, boxers and Dobermans, often used as police dogs, showed significant differences from other breeds in the network associated with vision and smell. Dogs bred for sporting combat displayed changes in the network related to fear, stress, and anxiety responses.
The researchers were particularly intrigued by differences between dogs bred for sight hunting and those bred for scent hunting. Dogs specializing in scent hunting showed differences not in the primary regions of the brain that detect smells but in the more advanced areas that help them process and communicate that information, which made sense to Hecht.
“I’ve heard trainers working with scent dogs say that you don’t need to train a dog to smell something,” she said. “You just need to train them to report it.”
One limitation of the study, according to Hecht, is that all the dogs examined were pets, not working dogs. “It’s incredible that we can see these differences in their brains, even though they’re not actively performing these behaviors.”
She also noted that her findings could have broader implications. The fact that we are altering species around us to such an extent that it changes their brain structure is “profound.” “I think it’s a call to be responsible about how we’re doing this and how we’re treating the animals we’ve done this to,” she concluded.
Illustration: petepop. This content was created with the help of AI and reviewed by the editorial team.
