The dog has been evolving paw in the hand of man for thousands of years now. But researchers continue to make surprising discoveries about it. The latest: the fact that the brains of newer dog breeds are larger than those of older breeds. Difficult to explain…
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[EN VIDÉO] These dogs are little geniuses! All dogs are smart. But some are real little geniuses! They know…
The dog is man’s best friend. That’s why researchers like to learn more about him. But it’s not just that. What they also hope, by studying the different dog breeds, is to succeed in shedding light on the factors that affect brain size. To finally understand why the human brain appears exceptionally large compared to the size of our body.
For decades, a researcher from Eötvös Loránd University (ELTE, Hungary) has therefore collected skulls of dogs of different breeds. A veterinarian then reconstructed the dogs’ brains based on scans. And the canine brain and tissue bank of the ELTE made it possible to validate the brain volumes calculated from real brains. Enough to obtain data on 159 breeds of dogs and 48 specimens of wolves.
First observation: dogs with a weight comparable to wolves – around thirty kilos – have a smaller brain than their wild cousins: 100 cm3 against 130 cm3 approximately. This confirms a hypothesis put forward by the researchers. That the brains of domestic animals are up to 20% smaller than those of their wild ancestors because life alongside humans is more peaceful. They have little to worry about hunting for food or guarding against predator attacks.
Hypotheses that remain to be confirmed
But the researchers were surprised by another observation. Above all, they expected to see the size of the brains of dogs vary according to the tasks that the breeds perform. From hunting or working dogs to companion dogs. However, what the scientists draw from this first complete study concerning the size of the brain of different breeds of dogs, it is above all that the more a breed of dog is genetically distant from wolves, the more the relative size of its brain increases.
Remember that the domestication of the dog dates back some 25,000 years. But that for about 10,000 years dogs and wolves have remained very similar in appearance. With agriculture, pastoralism, the enrichment of populations, the tasks that were then assigned to our best friends have diversified. They became guard dogs, herding dogs, hunting dogs and companion dogs. And finally a large part of the current more than 400 races only emerged during the last two centuries.
The researchers note that the increased brain size of newer dog breeds cannot be explained by the tasks assigned to them. Nor by their life cycle. They refer to work that also shows that ancient races are less attentive to human signals. They also bark less. Thus presenting marked differences in communication compared to modern races. Scientists thus imagine that if the most recent dog breeds have larger brains, it could be due to a more complex social environment, urbanization or even adaptation to more rules and expectations. A set of hypotheses that will still have to be verified…
