A new study found evidence that dos developed in physical ways to present “lovely dog eyes” as a way to connect with humans.
The study compared the facial muscles (肌肉) of dogs and wolves, which share ancestral history. Dogs broke off from wolves after being domesticated (驯化) about 33,0000 years ago. During that time dogs changed physically and behaviorally to fit life with humans.
The researchers examined the heads of six dogs and two wolves for comparison. They found the facial structure of both animals was mostly very similar. But one major difference was found above the eyes. The dogs were found to have two well-formed muscles around the eye that were not present in the wolves. These small muscles permit dogs to raise their inner eyebrows, the study found.
Juliane Kaminski, a comparative psychologist from the research suggests this eyebrow-rising movement causes “a warm” feelings in humans because it makes the dogs’ eyes appear larger. This expressions also makes the dog lo more like a human baby. The eye movement is similar to that which humans make when they are sad.
“The evidence is very obvious that dogs developed a muscle to raise the inner eyebrows after they were domesticated from wolves,” Kaminski said.
In a separate part of the study, the researchers observed how 27 dogs and nine wolves interacted with a human. “We also studied dogs’ and wolves’ behavior. And when exposed to a human for two minutes, dogs raised their inner eyebrows more and higher than wolves,” Kaminski said.
The researchers suggest that the eye movements developed over time as a way for dogs to get humans to do things for them, such as giving then food, care or attention.
The only dog species in the study that did not have the muscles was the Siberian husky, which is an ancient kind of dog. The husky could be the best living example of what the link between dogs and wolves looked like.
Kaminski said the main limitation of the study was the small number of dogs and wolves used. This means further study will be required and should include other ancient dog species. The work could also be extended 10 other animals with which humans have developed close relationships, including horses and cats.
【小题1】What is the difference found between dogs and wolves?| A．Dogs have bigger eyes. |
| B．They have different ancestors. |
| C．They have easily distinguishable faces. |
| D．Dogs have additional muscles around the eyes. |
| A．Dogs have developed in order to get along with humans. |
| B．Dogs have learned facial expressions from human babies. |
| C．Dogs are intentionally raising their eyebrows to please humans. |
| D．Dogs have changed their behaviors to get food from humans. |
| A．It has lovelier eyes than the other dogs. |
| B．It seems much more like a wolf than a dog. |
| C．It can raise its eyebrows higher than most dogs do. |
| D．It is better at linking with humans than an ordinary dog. |
| A．The evolution of the wolves. | B．Dogs’ ability to connect with humans. |
| C．The similarities between dogs and wolves. | D．Changes in dogs caused by domestication. |
