Humans have changed the world in countless ways — and among them is the evolution of dog ears.
Similar to how canine breeds come in a variety of sizes from mini doberman doggos to big St. Bernard round boys, dogs also have many different ear shapes.
Their relatives, wild animals like the coyote and the wolf, have upright ears that help sharpen their hearing, so any rustle of potential prey is heard. But, as the above video created by NPR’s Skunk Bear explains, many domestic dogs have floppy (and adorable) ears — it’s similar to domestic pigs when compared to wild boars, and farmed goats compared to wild goats.
So, as Seinfeld may ask, what’s the deal with these floppy ears?
According to Charles Darwin and other great scientific minds, it’s part of something called domestication syndrome, which also includes pets’ tendency to have shorter snouts and paler coats.
The traits can be traced back thousands of years, when early humans first started domesticating animals and breeding them to suit their needs. With these choices came other physical side effects. While some early scientists couldn’t pin down why these unplanned physical traits appeared, others had an idea: neural crest cells.
Neural crest cells form early in an embryo’s development and spread to almost every part of an animal’s body, affecting the way they develop, including how much adrenaline they produce. Less neural crest cells would mean less adrenaline production, and, as a result, an animal with a more diminished flight or fight response, a.k.a. a friendlier, more loyal companion.
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Scientists believe the diminished number of neural crest cells in domesticated animals also goes on to affect other parts of their bodies, like their ears, changing parts that a wild dog might need to survive.
Thousands of years of selective breeding have made certain traits attractive to humans, like light coats and floppy ears, an almost permanent trait of certain breeds.
Scientists aren’t sure if this idea based on neural crest cells is complete, but it is nice to think your golden retriever mix has floppy ears because of years of loyalty.