How genes drive your dog’s adorable and goofy behavior
A new study may help us understand our canine companions a little better. Scientists at the National Institutes of Health say they have discovered some of the ways genes can influence the behavior of certain breeds, such as herding dogs.
For about two decades, a team led by Elaine Ostrander of the National Human Genome Research Institute worked on the dog genome project. The ultimate goal of the project is to understand how genetics influence everything from a dog’s vulnerability to disease to its body shape. In their new study, published On Thursday in Cell, her team took a deep dive into the genetic underpinnings of canine behavior.
“Our study analyzed the genomes of thousands of dogs from hundreds of breeds and populations worldwide to reveal the genetic basis of the behavioral diversity of modern dogs,” Ostrander said in an email to Gizmodo. “We wanted to understand what in their genes makes sheepdogs move livestock, terriers kill vermin, hounds help us hunt, and so on.”
In all, they examined the genes of over 4,000 purebred dogs, mixed-breed mutts, semi-feral dogs and even wild cousins of domestic dogs. Based on this analysis, they identified 10 genetically distinct lineages. The team noticed that breeds with similar behavioral traits often clustered within these lineages, such as dogs that hunt primarily using their sight, compared to hunting dogs that rely on smell. They then compared what they found with data from a survey of more than 46,000 purebred dog owners.
From there, Ostrander said, the team “determined that each line had its own unique combination of behavioral tendencies that made them good at the job they were originally retained to do.” Terrier breeds, for example, tend to be more enthusiastic in chasing down potential prey, which makes sense since these dogs were originally bred to chase vermin. Finally, the team tried to find specific genetic variations that could drive behavior in certain breeds, including those that affect early brain development.
“For example, among sheepdogs, a behaviorally unique collection of breeds historically used for herding livestock, we have identified variants associated with genes controlling axon guidance, a process that underlies connectivity in the brain that modulates complex behavioral traits,” Ostrander said. These variants, some of which are linked to attention deficit hyperactivity disorder in humans, may help explain why sheepdogs tend to become incredibly focused while herding.
While humans have domesticated many animals, dogs were probably the first. And since then, they’ve become perhaps the most diverse creatures around, especially in the last few hundred years when deliberate dog breeding has become widely practiced (the pug looks very little like a husky, for example). But importantly, Ostrander and her team’s research also shows that many of the genetically determined behavioral differences we see in dogs now were not created by modern breeding.
“Instead, the early dog ’types’ probably became known in different parts of the world over thousands of years as people bred them for different purposes,” Ostrander said. “Our work shows that when people started categorizing dogs into ‘breeds’ several hundred years ago, they preserved single snapshots of the canine genetic diversity that existed in a particular place at a particular time, and that this genetic diversity had attitude toward behavior.”
This work is just the beginning for Ostrander’s team. They plan to continue looking for specific gene variants that govern the breed’s behavior. The same unique approach developed for this study should also allow them to study how a dog’s genetics can affect other complex traits, including the risk of certain diseases. And just as dogs have done for us so many times in the past, what we learn from this research may one day help humans too.
“Dogs and humans get the same diseases, those diseases manifest in much the same way, and everything we learn about canine genetic health impacts our understanding of our own susceptibility to disease,” Ostrander said.