Why do most dogs have brown eyes?

When a cute pooch stares up at you, all you want to do is bend down and scratch their belly. If you caught a wolf staring your way, you’d probably recoil in fear. Eye color may be at least partially to blame, according to a new study. Most wolves sport piercing yellow peepers, whereas most dogs have brown eyes— a hue humans may have selected for because it looks less threatening . The findings, reported today in Royal Society Open Science , fit with existing research on how people have changed the appearance of dogs over our shared history , says Molly Selba, an anatomist at the University of Maryland Eastern Shore who was not involved with the work. “It makes sense that eye color would be just one more place where humans have left their mark.” People have been molding dogs since they were first domesticated— perhaps 20,000 or more years ago —choosing animals that are friendly, obedient, and good at working for us. We may have also changed what they look like, from their big eyes to their large foreheads. Such “neotenous” traits are reminiscent of our own children, transforming dogs not only into companions, but fur babies. But where does eye color fit in? The light-colored irises of wolves may be useful for communication in the wild because they make the size and direction of the pupils more visible, allowing the animals to better convey messages such as gaze direction and dominance. Yet more tha...
Source: Science of Aging Knowledge Environment - Category: Geriatrics Source Type: research