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The Amazing Change in Dogs' Eyes

There’s been an amazing change in the eyes of dogs.

The domestication of dogs is one of the most compelling stories in human history. The way our two species have evolved to work and live together is astonishing. Now we have a new, fascinating piece of science to add to our body of knowledge about the domestication process.

Dogs Focus on Humans

It's well-known that dogs have learned to read humans' body language exceptionally well. It's no surprise, either. Domesticated dogs must be able to figure out what their humans want them to do to be kept safe and fed.

In fact, there's plenty of research into dogs' understanding of human body language. For instance, dogs in one study were more reluctant to follow instructions given by an angry person (Gartman, 2015).

Evolution and Dog Communication

Communication, of course, goes two ways, and dogs have also been working on how to let us know what they want and are thinking. They've gotten pretty good at it too. They use their tails to communicate an awful lot. Ear position is another significant way that dogs let people know their intentions. Learn more about how dogs communicate: "Canine Body Language: What Is Your Dog Saying?"

Now, a new study has found that dogs' faces can make complex emotional expressions that wolves' faces can't (Juliane Kaminski, 2019). That's due, at least in part, to two extra muscles that dogs have around their eyes (and wolves don't). Those muscles allow dogs to make more varied "puppy dog eyes" at humans than a wolf would be able to.

That means that those muscles have evolved, likely as a result of dogs' need to communicate better with humans. Not only that, but the researchers have also stated that the time needed to produce the two new muscles in dog's faces (which can make their eyes rounded, bigger, and droopier voluntarily) was incredibly short compared to how long evolution usually takes to work.

So, when your dog sees that you're holding a treat and gives you an adorable, longing look, part of it can be attributed to two small muscles that have evolved specifically to influence your reaction.

Works Cited

  1. Gartman, R. F. (2015, Oct. 29). Does affective information influence domestic dogs' (Canis lupus familiaris) point-following behavior? Retrieved from DOI: 10.1007/s10071-015-0934-5.
  2. Juliane Kaminski, B. M.-R. (2019, June 17). Evolution of facial muscle anatomy in dogs. Retrieved from DOI: 10.1073/pnas.1820653116.

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