Greger Larson, PhD from the University of Oxford joined Embark at the second annual Canine Health Summit to talk about the shared history of dogs and humans. For many of us, dogs are not just pets; they are family members. The science behind why we love our dogs is extensive, and researchers are constantly uncovering new biological and cultural findings that help explain the longstanding bond between dogs and humans.
Dr. Larson sheds some light on how science and archaeology have revealed just how deep the relationship between dogs and humans goes. He also explains what DNA can tell us about the human–dog bond and our cultural and evolutionary history.
“It is not overstating things to say that dogs are people, and we are our dogs.”
— Dr. Greger Larson, Professor of Evolutionary Genomics, University of Oxford
What do we share with dogs?
We share our diets
Dr. Larson explains a scientific study from 2009. Scientists compared ancient human bones and dog bones to those of other animals from the same time period. The results showed that the isotopic signatures (chemical fingerprints) from the human bones matched those of the dog bones—but didn’t match any of the other animals.
This finding showed that people and dogs lived in the same space and ate the same food, highlighting a very close relationship. Over time, as humans’ diet changed, so did dogs’. When humans ate more protein, dogs did, too. We can see these diet changes mirror each other consistently over at least the last 10,000 years.
What does this scientific study have to do with pumpkin spice lattes?
Dr. Larson compares this shared dietary history to today. The pumpkin spice latte is a popular seasonal beverage in the United States, and has grown in popularity more recently in other parts of the world. What came next? Pumpkin spice dog treats.
Evolutionary history of dogs and humans
Science shows that we also climbed the highest mountains with our dogs.
In a study of people who live on the Tibetan Plateau, a low-oxygen environment near the Himalayan mountain range, scientists discovered a gene. This gene, called EPAS1, allows people at high elevations to get enough oxygen from the atmosphere to live at high altitudes without getting altitude sickness.
Of course, the people who lived on the Tibetan Plateau had dogs with them. Another study that looked at dogs from the same area found the same gene, EPAS1, allowing dogs to survive in high-altitude, low-oxygen environments. We both have the same gene to help us survive at high altitudes, and that gene works the same way in humans and in dogs.
In fact, this gene for altitude adaptation is so important that Embark tests for it. Find out if your dog has the genetic variant to help them withstand high altitudes with an Embark dog DNA test.
Genetics is just one of the many ways we see the shared history of dogs and humans.
Dogs in art and literature
Throughout history, people have long included dogs in our artwork and literature. Many ancient civilizations followed a tradition called cynocephaly, depictions of human figures with the heads of dogs or jackals. Examples include the Egyptian god Anubis and the Telchines in Greek mythology.
These representations reflect the shared history of dogs and humans, showing that even since ancient times, we have become so dependent on our dogs that we blend humans and dogs into one figure.
Even today, researchers are looking into how humans and dogs look alike—and might even resemble each other. Not long ago, psychologist Dr. Sadahiko Nakajima conducted a study that supported the idea that people really do look like their dogs. His research suggests that the reason why is in the eyes.
We migrated together
When the first people crossed over the Bering land bridge to the Americas, did they bring dogs with them?
Dr. Larson’s team sought to find the answer to this question by looking at mitochondrial DNA. Their findings suggest that the first people who came to the Americas definitely brought dogs with them, and these indigenous dogs were present around 15,000 or 16,000 years ago. One clear pattern in the history of dogs and humans shows that wherever humans were, dogs were not far away.
These first people and first dogs in the Americas had unique genetic signatures that were distinct from any other human population or dog population on earth.
Shared demographic history of humans and dogs
Dr. Larson explains a recent study that details how the population of Indigenous people in the Americas declined drastically after Europeans arrived in the fifteenth century. Perhaps not surprisingly, the same thing happened with the native dog population.
A study called “The evolutionary history of dogs in the Americas,” which Dr. Larson’s team was involved in, showed that the majority of today’s dog population contain no detectable traces of indigenous American dog ancestry in their DNA. There is very little genetic evidence left from ancient American dogs today.
Learn more about what we know about these indigenous dogs and the arrival of European dogs, including the dogs on the Mayflower.
Life—and the afterlife
Do all dogs go to heaven?
To find out, Dr. Eric Tourigny studied British pet cemeteries and examined headstones from the Victorian period to present day. According to common religious beliefs at that time in history, heaven was reserved exclusively for people. There was no expectation that dogs would also go to heaven.
But as time went on, attitudes changed. We didn’t want to be in heaven without our pets. Now, it’s common to say that “all dogs go to heaven,” and we expect to be reunited with our beloved pets in the afterlife.
The tradition of associating dogs with the afterlife has deep roots. The ancient Aztecs revered dogs, particularly the Xolo, as guides to the afterlife. Today, Xolos are an important part of Día de los Muertos celebrations.
Our shared relationship with dogs exists not only during our lives, but also after death, too.
We share our microbiomes
By having such a close relationship with our dogs, we’re not only sharing our food, our homes, and our environment. We’re also sharing microbes, tiny microorganisms such as bacteria and viruses. There are helpful microbes that live naturally in or on our bodies, and harmful microbes (pathogens) that cause infections and disease.
A few years ago, scientists discovered that dog-owning adults share skin microbiota with their dogs. In another, more recent study, scientists found that dogs and their owners often share the same allergies, too, which is partly a result of sharing these microbes.
We can also share pathogens and infections with our dogs, although we might not want to. Several types of bacterial and viral infections can be transmitted from humans to dogs, or vice versa.
Watch Dr. Larson’s full talk:
The dog—human bond
We have a tendency to think that what’s good for us is also good for our pets, whether that’s our diet, our home, or our lifestyle.
But the dog–human bond doesn’t stop there. At the Canine Health Summit, Victoria Cussen, PhD, CAAB; Marty Becker, DVM; Brenda S. Kennedy, DVM, MS; and Mariana Serao, PhD joined us at Embark to talk about the depth of this relationship.
Humans and dogs are different species, but we mimic each other quite a bit. Dogs also share some of the same psychological needs that we do. Pet care often focuses on keeping pups physically healthy, but their emotional and mental well-being is just as important.
As humans, we tend to get bored when stuck at home with nothing to do. Dogs can experience a similar type of boredom, which is why it’s important to give them a chance to exercise their brains with dog-friendly tasks. Certain breeds, such as herding breeds, benefit even more from having a “job” to do, but all dogs need mental stimulation.
“All dogs have the same suite of basic psychological needs,” says Dr. Cussen. “They learn, they have goal-directed behavior, they have motivations, they have emotions; they are thinking, feeling creatures.”
As Dr. Serao explains, dogs need to put their brains to work, too—what veterinarians call “cognitive stimulation.” Whether that’s scatter feeding (scattering kibble in the grass rather than leaving it in a bowl), or giving your dog a puzzle toy to play with, cognitive stimulation can have a significant impact on a dog’s mental status over their lifetime.
“You’ve got to feed the body and feed the mind.” —Dr. Marty Becker
In the words of Dr. Kennedy, it’s our job to help our dogs maintain a healthy lifestyle, both mentally and physically, just like our own.
Watch the Canine Health Summit
Interested in more fascinating insights about dogs and health? You can watch all the sessions from the Embark Canine Health Summit on demand.