Modern dog breeds haven’t quite caught up with the brain-sized wolf, but the size difference is shrinking. Modern dogs have growing brains, and this may be due to their interactions with humans. New research published in the journal Evolution, studied the brain size of both modern and ancient dog breeds. The research team found that dogs’ brains became larger than they had genetically evolved from wolves.
It was an incredible discovery. “The results show that breeding of modern dog breeds is accompanied by an increase in brain size compared to ancient breeds,” says Eniko Kubini, senior researcher in the Ethology Department of the ELTE Institute of Biology, in a press release. “We couldn’t explain the races by their duties or life characteristics, so we can only speculate about their causes.”
In the study, a team from Hungary and Sweden used computer images of more than 850 dogs of 159 breeds to reconstruct the brains of different people and determine their brain volume. They compared the findings to 48 wolf samples. The data showed that a dog weighing the same as a wolf had about three-quarters the brain volume of a wolf. This confirms previous research that domestication reduces brain size by about 20 percent, because animals no longer have to hunt or fend for themselves, and are not in as much danger as they do in the wild.
“There is no need to maintain an energy-expensive brain, and the energy released can be directed towards other purposes, such as producing more offspring,” says László Zólt Garamseghi, an evolutionary biologist at the Center for Ecological Research in Hungary. “What matters to domesticated animals” newsletter.
But as expected, the more genetically distant a dog breed was from the wolf, the larger its relative brain size was. And it didn’t matter whether the dog had energy-sucking responsibilities like herding or guarding.
“Perhaps a more complex social environment, urbanization, and greater adaptation to rules and expectations caused this change that affected all modern races,” says Kubini.
The study suggests that functional category, skull shape, longevity, and litter size have nothing to do with relative brain size. The team believes the findings are further supported by the independence seen in ancient breeds, particularly their tendency to bark less and respond less to human cues than modern breeds.
“Different dog breeds live at different levels of social complexity and perform complex tasks that likely require more brain power,” Niklas Kolm of Stockholm University said in a press release. “Therefore, we hypothesize that selective pressures in the brain may differ between dog species, and we can detect differences in brain size between breeds based on the tasks they perform or their genetic distance from wolves.”
Source: Port Altele
