If you’ve ever seen a wolf, you’ve seen its pointed ears. Then if you’ve seen someone’s pet dog (or maybe even yours), you may have noticed their floppier ears. This phenomenon isn’t limited to just dogs, many other domesticated animals have exhibited something similar. This includes, but is not limited to, cats, horses, sheep, and pigs. This pattern is so common between domesticated animals that even the big boy of evolution himself, Charles Darwin, got invested. So why exactly do dogs have floppy ears?
Wolves and Pointy Ears
Those of you with dogs, or any domesticated pet for that matter, probably know that they can’t survive out in the wild. Like at all. Look at the image of the dog to the right and tell us he would survive for more than three minutes in a mild breeze. We’re waiting…
Having ears of a floppy variety has little advantage out in the wild–that’s why wolves have pointed ears. Sparing a deep delve into how ears are designed; suffice to say that better ears funnel sound waves into your head better. For an animal requiring 360 degree awareness, pointed ears make sense. They can spin around (kind of), and better focus on sound coming from different directions. Is that the best ear design ever? Maybe not; but it sure beats having ears that cover the hole meant to capture noise.
For more on dogs, check out: How Were Dogs Domesticated?
Why Do Dogs Have Floppy Ears?
It probably isn’t very surprising to hear that the answer to this question lies in genetics. Further, we doubt that you’re surprised to learn that this phenomenon seems to exclusively be at the hand of animal domestication. You, like Darwin, probably figured it out because all sorts of animals domesticated by humans exhibit this trait. These shared traits between domesticated animals (like floppy ears and shorter snouts) have since been dubbed “domestication syndrome,” by the way.
We can point to neural crest cells for domestication syndrome. We know these cells affect the physiology of an animal, which would explain why domestic animals look so different from their feral ancestors.
But under natural selection, some rules still apply. A trait should become more apparent because it is advantageous for that trait to be present. So what would floppy ears, something less advantageous than pointy ears, be selected for?
You probably guessed the answer was humans. Selectively breeding dogs with just the floppy ears would make floppy ears more prevalent within the dog population. But we probably weren’t just looking for floppy-eared puppies.
There’s one more thing with neural crest cells–and that’s the adrenal glands. The long and short is that neural crest cells affect the fight or flight response of an animal. So we probably bred animals with a specific level of neural crest cell–one that made the animal less likely to fight or flee from a human.
Over time, we kept breeding tamer animals, and here we are–domestic animals and dogs with floppy ears.
Want an excuse to look at more dogs? Look at dogs and consider eating a bagel for breakfast here.