Scientists in Sweden have shown that some wolf cubs, such as dogs, are able to play with humans. It is an unexpected result, one that suggests that the ancestors of the dogs were prepared for domestication.
A new study published in iScience presents evidence showing that some wolf cubs, with a little breath, will retrieve a thrown ball and return it to an unknown place. human. In other words, they can play to search.
This may not seem like a big problem, but wolves are not supposed to really Respond to human social cues. Dogs, of course, are absolute professionals in understanding human-directed signals, whether physical or verbal in nature. Mature wolves, on the other hand, do not play to look and do not seem to capture human gestures, as noted.
The new article, therefore, raises an intriguing question: Did the ability to understand and react to human social cues arise as a product of domestication, or did it already exist among the ancestors of dogs? The new research points to the latter, suggesting that this ability precedes domestication.
“When I saw the first wolf cub recovering the ball, I literally got goosebumps, ”said Christina Hansen Wheat, co-author of the study and researcher at the University of Stockholm, in a press release. “It was so unexpected, and I immediately knew that this meant that if variation in human-led game behavior exists in wolves, this behavior could have been a potential target for early selective pressures exerted during dog domestication.”
It is an intriguing possibility, but the new document contains problematic gaps that should be addressed if this hypothesis is taken seriously.
These observations were made during a larger test to compare the behaviors of dog and wolf puppies. In a particular subtask, the researchers sought to determine to what extent, if they did, wolf cubs could respond to human social cues. This test was performed in the context of the human-directed game, which according to the authors had never been tried before.
For the experiment, Hansen Wheat, along with her Co-author Hans Temrin, also from the University of Stockholm, took 13 wolf cubs from three litters born in 2014, 2015 and 2016, all hand bred by the team since they were 10 weeks old. These wolf cubs, unlike those born in nature, were habitually accustomed to humans.
During the test, a wolf cub was placed in a room with a person unknown to them. The person, known as the puppy advisor, threw a tennis ball across the room. The wolf cubs had not been trained before the experiment, nor were they previously exposed to tennis balls. The adviser encouraged the puppies to take the ball and return it. Puppy responses were ranked on a scale from 1 to 5, in which 1 represented zero interest in the ball and 5 represented total cooperation, which included getting back the ball to the human. This test was repeated three consecutive times for the 13 wolf cubs. Here are the results as summarized in the document:
Three wolves, all from the litter of 2016, completely recovered the ball at least twice, and one of those wolves completely recovered the ball three times (Score: 5). One of the wolves completely recovering the ball twice also played with the ball in one of the tests, but ignored the caller’s evaluator’s call (Score: 3). A wolf from the litter of 2014 and one from the litter of 2016 showed some interest in playing with the ball in at least one test, but they aborted (Score: 2). Eight wolves (four from the 2014 litter, both from the 2015 litter and two from the 2016 litter) showed no interest in the ball in any of the three trials (Score: 1).
Then three of the 13 wolves pUPS completely recovered the ball. This is evidence, say the authors, that the ability of canids to understand and respond to human social cues existed before domestication.
“This suggests that, although it is probably weird … The expression of human-led behavior in ancestral populations could have been an important objective for the early selective pressures exerted during dog domestication, “the authors wrote in their study.
Kathryn Lord, a wolf expert at the University of Massachusetts School of Medicine in Worcester and the Broad Institute in Cambridge, who was not involved in the study, said it is an “exciting” job.
“It is possible that they were unnecessarily harmed by using puppies that had not previously been socialized with strangers, since previous work on the subject in dogs was done with dogs that socialized with both familiar and strange people,” Lord told Gizmodo. “I would hope they had found even more wolf cubs responding successfully to the human request if they were used to strangers in general.”
There are some important warnings. to point out, however.
With only 13 wolf pups studied, the researchers relied on a painfully small sample size. Given the somewhat subjective nature of the experiment (were the pups really playing to look for?), It would be wise for this team and / or other researchers to duplicate the experiment with a larger batch of wolf cubs. It would also be good to know why three wolf cubs in one litter were inclined to play, while neither of the other two litters showed inclination. The question of why wolf cubs, but not adult wolves, are predisposed to play fetch, also remains unanswered.
It is also important to note that these wolf cubs were accustomed to humans. In an environment of early domestication, protoperros would also have become habituated to humans, which means that they were already going through the selective domestication processes. Therefore, it is not immediately clear that this cognitive ability existed in wolf cubs before domestication.
In short, this is an intriguing but incomplete study. It sets the stage for future research, as we seek to better understand dogs and why they are so willing and happy to play with us.