Dogs’ Eyes Have Changed Since Humans Befriended Them
Two specialized muscles give them a range of expression that wolves’ eyes lack.
Dogs, more so than almost any other domesticated species, are desperate for human eye contact. When raised around people, they begin fighting for our attention when they’re as young as four weeks old. It’s hard for most people to resist a petulant flash of puppy-dog eyes—and according to a new study, that pull on the heartstrings might be exactly why dogs can give us those looks at all.
A paper published today in the Proceedings of the National Academy of Sciences found that dogs’ faces are structured for complex expression in a way that wolves’ aren’t, thanks to a special pair of muscles framing their eyes. These muscles are responsible for that “adopt me” look that dogs can pull by raising their inner eyebrows. It’s the first biological evidence scientists have found that domesticated dogs might have evolved a specialized ability used expressly to communicate better with humans.
For the study, a team at the University of Portsmouth’s Dog Cognition Centre looked at two muscles that work together to widen and open a dog’s eyes, causing them to appear bigger, droopier, and objectively cuter. The retractor anguli oculi lateralis muscle and the levator anguli oculi medialis muscle (mercifully known as RAOL and LAOM) form two short, straight lines, which connect the ring of muscle around a dog’s eye to either end of the brow above.
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That suggested the movement is to some degree voluntary. On our side of these longing glances, research has also shown that when dogs work these muscles, humans respond more positively. And both man and mutt benefit from a jolt of oxytocin when locked in on each other.
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In this case, those eyebrow-raising muscles do appear to be an addition to dogs’ anatomy. In the four gray wolves the researchers looked at, neither muscle was present. (They did find bundles of fibers that could be the precursors to the RAOL and LAOM.) In five of the six breeds of dogs the researchers looked at, both muscles were fully formed and strong; in the Siberian husky, the wolflike, oldest breed of the group, the researchers were unable to locate a RAOL.
https://www.theatlantic.com/science...-eye-muscles/591868/?utm_source=pocket-newtab
Two specialized muscles give them a range of expression that wolves’ eyes lack.
Dogs, more so than almost any other domesticated species, are desperate for human eye contact. When raised around people, they begin fighting for our attention when they’re as young as four weeks old. It’s hard for most people to resist a petulant flash of puppy-dog eyes—and according to a new study, that pull on the heartstrings might be exactly why dogs can give us those looks at all.
A paper published today in the Proceedings of the National Academy of Sciences found that dogs’ faces are structured for complex expression in a way that wolves’ aren’t, thanks to a special pair of muscles framing their eyes. These muscles are responsible for that “adopt me” look that dogs can pull by raising their inner eyebrows. It’s the first biological evidence scientists have found that domesticated dogs might have evolved a specialized ability used expressly to communicate better with humans.
For the study, a team at the University of Portsmouth’s Dog Cognition Centre looked at two muscles that work together to widen and open a dog’s eyes, causing them to appear bigger, droopier, and objectively cuter. The retractor anguli oculi lateralis muscle and the levator anguli oculi medialis muscle (mercifully known as RAOL and LAOM) form two short, straight lines, which connect the ring of muscle around a dog’s eye to either end of the brow above.
...
That suggested the movement is to some degree voluntary. On our side of these longing glances, research has also shown that when dogs work these muscles, humans respond more positively. And both man and mutt benefit from a jolt of oxytocin when locked in on each other.
...
In this case, those eyebrow-raising muscles do appear to be an addition to dogs’ anatomy. In the four gray wolves the researchers looked at, neither muscle was present. (They did find bundles of fibers that could be the precursors to the RAOL and LAOM.) In five of the six breeds of dogs the researchers looked at, both muscles were fully formed and strong; in the Siberian husky, the wolflike, oldest breed of the group, the researchers were unable to locate a RAOL.
https://www.theatlantic.com/science...-eye-muscles/591868/?utm_source=pocket-newtab
