Here’s how selective breeding changed our dogs’ brains
Anyone who is familiar with a wide variety of dog breeds can tell you that some seem to have an innate talent for certain jobs or personality traits that are consistent across the breed. German Shepherds are very successful in police work, for example, while Golden Retrievers are tolerant and gentle with children. Despite the fact that these stereotypes are generally accepted in countless breeds for countless traits, little scientific research has been done on the subject. Until now.
The researchers set out to determine whether there was a neurological basis for these traits. Was the brain of a breed known to be excellent scent hunters any different from a breed that is excellent sheepdogs? Do the brains of dogs bred to be companions behave or look differently than a working breed? Unexplored questions such as these have led researchers to explore the brains of dogs using MRI technology.
The authors of the study wanted to see precisely whether or not selective human breeding changed the organization of the brain in dogs and if so, how the brain had changed. To do this, they performed MRI scans of 62 male and female dogs of 33 breeds.
The researchers examined each dog’s entire brain using independent components to analyze each brain in a coherent fashion. They found that specific regional subnets vary widely from breed to breed. The variations observed were not only in brain size, total body size or the shape of the skull.
Image credit Barn Hunting Association LLC
The team used phylogenetic analysis which showed that most of the changes occurred in the terminal branches of the dog’s phylogenetic tree. And what does that mean? This indicates that changes have occurred evolutionarily recently through human selection in individual races.
When breeders chose to mate particular animals because of their high exposure of a desired trait, such as being an excellent watchdog, those choices led to brain changes in the breed in a short period of time.
One of the study’s authors, Erin E. Hecht, is an Assistant Professor in the Department of Human Evolutionary Biology at Harvard University. She said News week:
“These differences are at least partially due to selective breeding for particular behaviors.”
The study states “that there has been a strong recent selection pressure on brain organization in individual breeds of dogs, suggesting that the effects of humans on the brains of dogs can occur very quickly over the course of the period. ‘evolution,’ she said.
“I think it’s pretty deep that our species shaped the brain of another species on the planet,” Hecht explained.
Hecht noted that the subject dogs who participated in this study were, to the best of their knowledge, family dogs. They are not actively doing the work their race brains are predisposed to, indicating that these traits or skills are hardwired. She said News week,
“This means that despite these dogs not actively performing these skills, we can still see specializations in their brains for them, which I think is pretty amazing! I imagine if we were to study dogs that actively adopt these behaviors, we could see even clearer effects. ”
This is what the team plans to study next. Does your dog exhibit traits that you just know are wired into his brain? Do these skills or attributes help you guess which breeds are present in your mixed breed rescue puppy?