Why do some dogs have floppy ears?
There are an incredible amount of differences between dogs of different breeds, and one of those differences is in their ears. Flap ears, pointy ears, semi-pointy ears… the possibilities are endless! Why do dogs have floppy ears? Do floppy ears have a purpose or are they just that way?
The answer lies in the history of dog domestication.
The Russian Silver Fox Experiment
Since 1959, researchers have been studying dog domestication by domesticating silver foxes. It is common knowledge that our current dogs descend from a common ancestor of wolves, but foxes were chosen for this experiment because they are easier to work with and keep than wolves.
After decades of research, several incredible discoveries have been made about the characteristics of silver foxes undergoing domestication.
For example, Dmitri Belyaev, the researcher who began this experiment, noted that many domesticated animals retain their youthful features into adulthood, including floppy ears.
Even prick-eared dogs, or other prick-eared canids such as wolves and foxes, are born with floppy ears. Their ears gradually become erect as they grow and develop.
Belyaev decided to test his hypothesis that these floppy-eared genes were linked to tameness through his study of foxes. The original foxes were a population of wild foxes, with no evidence of domestication.
Of the hundreds of foxes, the researchers tested each fox for their level of tameness, then selected the 10% most tame foxes to reproduce for a future generation.
Within six years — or six generations — these foxes selected for tameness alone developed many of the characteristics of domestic dogs.
Behaviorally, they licked people's hands, whined when people left, enjoyed being picked up and petted, and even wag their tails at the sight of people. However, behavior wasn't the only thing that changed. Selected only for their tame behavior, the foxes' appearance also changed.
Foxes selected and bred for tameness developed floppy ears and curled tails. Their stress hormone levels dropped to half that of wild foxes' stress hormone. They also began to produce more serotonin, or the "happy" chemical.
Their faces became shorter and rounder, and much more dog-like than their wild fox ancestors. Their coat patterns also changed, they developed mottled patterns and their overall body shape became shorter and rounder.
The foxes began behaving like dogs in other ways as well. A trait of domestic dogs that is rare among a variety of other animals is the ability to follow human gaze. Foxes selected for tameness began to follow human gaze just as well as dogs!
While the fox research is still ongoing, it has provided us with an incredible amount of information about how the dog taming process likely worked.
It is clear that the genes that play a role in animals' tameness also play a role in their physical characteristics. The foxes that are tame and domesticated look "cute" and juvenile - floppy ears, curled tails, unique color patterns and round bodies.
This likely plays hand-in-hand with how dogs were originally selected. The first wild canids to be tamed and to work with humans would very likely have been selected for temperament alone.
However, the animals probably also looked "cuter" and were even more often chosen for breeding, resulting in a wide variety of floppy-eared dogs with calm and loving dispositions.
We can see how these changes have been at work just by looking at the dog breeds we have around us today. The more "primitive" breeds believed to be closer genetically to their wild ancestors are Huskies, Malamutes, Akitas, and other similarly built dogs.
It's pretty obvious to see the characteristics they share with wolves — their size, their prick ears, and their more aloof temperament. These breeds are all often associated with working dogs with a more serious mindset than, say, a Golden Retriever.
In the same sense, the dogs often thought to be the cutest and friendliest correspond to the characteristics of domestication observed in the foxes.
Many breeds bred for companionship have floppy ears, soft facial features, rounder body shapes, and some may have curled tails.
So while genetics are complicated, it can be assumed that dogs have floppy ears because floppy ear genes are linked to genes for friendliness.
Are floppy-eared dogs friendlier than prick-eared dogs?
Not necessary. Genetics is complicated, and dogs are all individuals within their breeds too! It is likely that the first dogs with floppy ears were created by selection for friendliness, but that does not mean that these "friendly" genes cannot exist in a dog with prick ears.
It also doesn't mean that dogs with pricked ears are unfriendly. Prick-eared dog breeds tend to tolerate the majority of people while loving their particular people. They are usually not everyone's friends, but there are certainly exceptions.
If you want a friendly dog, you can certainly be successful by choosing a dog with a family history of friendly dogs. Today, a dog can have any appearance combined with almost any type of character.
The best dog is the one that fits your lifestyle and goals. The best way to set yourself up for choosing and raising a dog is to research a breed's history, the dog's parents, grandparents, and other relatives, and read about training a dog.
You will (hopefully) have to live with your dog's behavior for a decade or more, so you should choose your dog based on temperament and behavior first, and appearance second.
Fortunately, with the wide variety of breeds available, you can probably find the dog you're looking for!
This BLOG has been posted on our website as a guest blog with the author's approval.