Selective Breeding Of Canines Has Changed Their Brains, Finds Study

Dogs have been selectively bred for desired physical traits and favorable behavior over centuries. This controlled evolution has shaped their brains too.

Breeding as we know it today is a fairly new invention. For the most part, it was not until the 19th century that people began to document canine bloodlines and categorize dogs into specific breeds rather than generic types such as hunting dog, hound, herding dog, or lap dog. Breeders ranged from noblemen creating a better retriever to shepherds refining herding ability for their particular livestock.

A study scanned the brains of 62 purebred dogs of 33 breeds and found that their brains were not alike. This offers a starting point in understanding the link between brain anatomy and behavior. Different breeds were found to have different shapes to various brain regions.

It should be noted that these distinctions were not simply the product of head shape or the size of the dogs’ brains or bodies, researchers reported in the Journal of Neuroscience.

Through selective breeding, “we have been systematically shaping the brains of another species,” Erin Hecht, an evolutionary neuroscientist at Harvard University, and colleagues conclude.

The MRI scans were taken of dogs with normal brain anatomy at the Veterinary Teaching Hospital at the University of Georgia at Athens. The study was not intended to directly associate brain shape with behavior, though it does hint at the relationship. Researchers pointed out that certain areas of the brain, notably the smell and taste regions, displayed the most variability between breeds. Those groups are involved in specialized behaviors that often serve humans, such as hunting by smell, guarding and providing companionship to people, earlier studies have suggested.

The authors assumed the dogs in the study were all pets. It is possible that dogs rigorously trained for specialized work — such as sheep herding, bomb-detecting or guiding the blind — might have even more distinct brains.