Dog brains are getting bigger

Research reveals that genetically more modern dogs tend to have larger brains. It seems our four-legged companions are getting smarter for a while now, despite the fact that the brains of wild animals tend to shrink with domestication. what are the causes of this phenomenon?

Modern dog breeds furthest genetically removed from wolves have relatively larger brains than ancient breeds thousands of years old, a team of scientists from Hungary and Sweden has found.

As László Zsolt Garamszegi, from the Center for Ecological Research in Vácrátót, Hungary, and co-author of the study, explains, the brains of domesticated animals can be up to 20 percent smaller than those of their wild ancestors. The most likely reason is that life for domesticated species is simpler than that of their wild counterparts. In the safe environment that humans provide, they do not have to fear attacks from predators or hunt for food. Therefore, there is no need to maintain a large brain, which is very energetically expensive, and the energy released can be used for other purposes, such as producing more offspring.

Is there a correlation between brain size and the specific tasks for which a breed was bred? Are there differences, for example, between lap dogs and hunting dogs?

The study reveals that the increase in brain size cannot be attributed to functions traditionally assigned to some breeds. Rather, everything points to the fact that this increase is influenced by the immersion of dogs in a complex social environment, that of humans, which is also much more technical than the natural environment in which dogs would live if they were wild animals without domestication. .

Specifically, wolves have an average brain volume of 131 cubic centimeters, associated with an average body weight of 31 kilograms. In the case of dogs of a similar weight category and genetics not dissimilar to wolves, the brain volume is approximately 100 cubic centimeters. This confirms that domestication caused a decrease in the size of the brain in dogs, at least in those of the more primitive type described. What surprised the researchers, however, is that the further a dog breed genetically distances itself from the wolf, the larger its relative brain size becomes, thus reversing the initial trend.

The skull of a vizsla dog and a 3D model of its brain, made from high-resolution CT scans. (Image: Kálmán Czeibert)

The domestication of dogs began approximately twenty-five thousand years ago, but for ten thousand years, dogs and wolves did not differ in appearance. Many ancient breeds, such as sled dogs, still resemble wolves today. However, the transition to stable settlements, agriculture, herding, and the accumulation of wealth placed quite different tasks on the dogs. From then on, watchdogs were required to protect people, sheepdogs to guide flocks of sheep and other animals and prevent their dispersal, hunting dogs to help humans hunt, and even lapdogs to keep pets company. people and live in close contact with them.

However, a significant part of the breeds whose physical appearance is further removed from that of wolves only arose from the industrial revolution, mainly in the last two centuries, as dog breeding has become a hobby, such as as Enikő Kubinyi, from Eötvös Loránd University in Budapest, Hungary, and a member of the research team, explains.

The study is titled “Evolution of relative brain size in dogs—no effects of selection for breed function, litter size, or longevity.” And it has been published in the academic journal Evolution. (Fountain: NCYT by Amazings)