It's no secret to those of us with dogs that these creatures are special. With their love and loyalty to us coupled with their uncanny ability to read our emotions better than many members of our own species, they seem designed to be our best friends. They live, play, work, herd, and hunt with us, and have done so for thousands of years. In that time they have earned the title of "Man's (humankind's) best friend", and a special place in our hearts. Where did our best friends come from? How long have they been with us? Just how special are dogs? In this blog we will journey across time, space, and species in attempt to answer these questions.
The timeless quality of a campfire is even more tangible when sharing that experience with your dog(s).
Where did dogs come from?
The domestic dog is a mammal and member of family Canidae (the Canids), which includes wolves, coyotes, foxes, jackals, and more. Its scientific name is given as either Canis familiaris or Canis lupus familiaris, depending on the source. Why? Because its ancestor and closest living relative, the Gray Wolf (Canis lupus), is so genetically similar (98.8% identical) that the domestic dog may be a subspecies of the wolf rather than a separate species. Wolves and dogs exhibit similar behaviors and can even successfully breed (one definition of a species is that it cannot breed with other species), but alas have diverged due to their different associations with us.
The physical and behavioral similarities between dogs and wolves is glaringly obvious.
How long have dogs been with us?
Let's start with what we know for sure: dogs came from wolves in Eurasia at least 15,000 years ago. Some studies have concluded as far back as 30,000 years! Wow! This was before cities, before farming, before any other animals were domesticated. We used to imagine that someone long ago came upon a litter of orphaned wolf puppies and proceeded to raise and tame them. In short, we domesticated wolves. However, what if they domesticated us as well? The more likely story may be that wolves began scavenging human campsites, the humans occasionally throwing a scrap of meat to the least cautious wolves. The less fearful, more friendly wolves stuck around camp, bred, and passed on this disposition to their offspring, each generation becoming more docile. The most recent research suggests this story may have played out twice; once in the east and once in the west. Beyond this, it's still a mystery.
Illustration by John James Audubon and John Bachman (1845-1848).
Dog domestication remains such a mystery because dog genetics are messy; they've traveled around the world with us, breeding back and forth with each other and with wolves (whose range also extends around much of the northern hemisphere) along the way. Dog genetics are also incredibly fascinating- hear me out before the eye roll. Of course we've been able to create dog breeds by breeding dogs for certain physical and behavioral characteristics, this is known as artificial (as opposed to natural) selection. However, this has only taken place over the past several hundred years. Remarkably, the behavioral trait of "Tameness" evolves with certain physical traits, including floppy ears, curly fur, shortened and/or curled tails, and different coat colors. Scientists are still working out the genetic underpinnings, but this process has been cleverly demonstrated in an experiment with foxes that has been ongoing since the late 1950's. Dmitry K. Belyaev, a Russian geneticist, examined a group of fur-farm foxes and selected the friendliest, most touchable foxes to breed. He exposed the pups to human contact, and with each successive generation he allowed only the friendliest 10% to breed. By the fourth generation, the fox pups were acting like dog puppies, wagging their tails, whining for attention, and licking their handlers.
One of my favorite National Geographic Magazine cover photos by photographer Robert Clark. This highlights how amazing the evolution of dogs is.
Groups of purebred dogs arranged by original function bred for- Source: The challenges of pedigree dog health: Approaches to combating inherited disease - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/272764819_fig4_Figure-1-Grouping-of-purebred-dog-breeds-The-215-breeds-recognized-by-the-UK-Kennel [accessed 25 Sep, 2016].
Belyaev's experiment- Belyaev himself at the top left with some of the experiment foxes, a wild Silver Fox (morph of Red Fox that he started with) at the top right, and later generations showing different colors, a curled tail, and floppy ears below. Images from http://blogs.scientificamerican.com/, alfre.dk, http://thefanhitch.org/V14N3/V14,N3News.html, and themysterioussilverfox.weebly.com.
Just how special are dogs?
Dogs behave in particular ways around us; they understand us better than any other species, including our closest living relative the Chimpanzee (Pan troglodytes). Dogs are empathetic, with examples range from catching yawns (when a human yawns, their dog might also), to responding to a human baby's cry similarly to how a human does, to responding to a stressed human by becoming showing the same symptoms of stress. They're the only non-primate to look us in the eyes without misinterpreting eye contact as aggression. Instead, we bond with eye contact. Dogs not only respond to our gaze but our voices, smell, and even gestures (like pointing a finger).
Dogs engage eye contact with us to bond.
When our dog looks us in the eyes, sees a picture of us, hears us, or smells us, levels of the hormone oxytocin increase in his or her body. When the tables are turned and we look our dogs in the eyes, pet them, or are just shown pictures of our dogs, our oxytocin levels also increase in response. Oxytocin, known as the "love hormone", is so called because it is involved with familial bonding, romance, and friendship. It plays a major role in the bonding of mother and child and romantic partners, being released when a mother nurses her child and when we hug, kiss, and cuddle with a loved one. Chemically, the dog-human bond is like a parent-child bond, for both involved. Behaviorally dogs share with children what is known as the "secure base effect", where the dog or child sees their guardian as a secure base under which they can safely interact with the environment. This makes dogs more likely to explore novel objects and experiences with their humans present, and more likely to run to their humans when frightened.
Dogs can reduce our fear and stress as well. Talking to and petting a dog lowers blood pressure. Interacting with dogs can relieve depression and help children with autism develop greater social skills. Dogs can further support our help with their abilities to smell chemicals associated with cancer in the body, changes associated with low blood sugar, and predict seizures. We undoubtedly have a unique and powerful relationship with our canine companions that benefits us both.
Dogs and humans- a partnership that changed the world
Humanity would arguably not be where it is today without dogs. Humans are slow and have a weak sense of smell; dogs' speed and strong sense of smell helped us to find prey and surround and hold it in place. Our weapons helped humans and dogs avoid injury during the hunt. Together we made a deadly combination; we may even be the primary cause of the Woolly Mammoth's (Mammuthus primigenius) extinction. Dogs have played important roles in hunting, farming, transport, and security as human society has evolved. Today they continue with the above as well as vital roles in the police and military, search and rescue, disability services, and more.
Dogs and humans hunting a mammoth, image from https://www.psychologytoday.com/.
Duck hunting, image from https://www.greenhead.net.
Herding dog, personal photo.
Service dog, image from https://www.petfinder.com/.
In this blog we've seen that our roots with dogs run deep; we've been together for a very long time and we've shaped each other into who we are today. Dogs and their human guardians have a strong love for each other. If you are in a position in which you can adopt a dog, and you are prepared for the commitment and responsibility of caring for one, I highly recommend that you do so and experience the world's oldest friendship for yourself.
Thank you for reading,
Jess
Sources:
On dogs and wolves, and the origins of dogs:
http://www.huffingtonpost.com/2014/01/17/dogs-wolf-ancestors-domestication_n_4616796.html
http://www.canidae.com/blog/2011/01/new-research-explains-why-dogs-arent-wolves/
http://www.theatlantic.com/science/archive/2016/06/the-origin-of-dogs/484976/
http://news.nationalgeographic.com/news/2013/03/130302-dog-domestic-evolution-science-wolf-wolves-human/
On dog breeds and Belyaev's fox experiment:
http://www.nature.com/scitable/topicpage/genetics-of-dog-breeding-434
http://www.bbc.com/earth/story/20160912-a-soviet-scientist-created-the-only-tame-foxes-in-the-world
http://blogs.scientificamerican.com/guest-blog/mans-new-best-friend-a-forgotten-russian-experiment-in-fox-domestication/
On dogs' special abilities and oxytocin:
http://news.nationalpost.com/news/we-really-do-love-dogs-as-if-theyre-our-furry-children-and-the-feeling-is-mutual-according-to-hormone-study
http://www.medicalnewstoday.com/articles/275795.php
http://www.businessinsider.com/special-abilities-that-show-how-smart-dogs-are-2016-6/#5-and-they-interact-with-us-as-if-they-were-children-5
http://www.medicalnewstoday.com/articles/262477.php
http://pets.webmd.com/features/pets-amazing-abilities?page=4
http://www.ncbi.nlm.nih.gov/pubmed/3236382
https://www.autismspeaks.org/science/science-news/autism-and-pets-more-evidence-social-benefits
http://psychcentral.com/blog/archives/2013/05/19/6-ways-pets-relieve-depression/
On humans and dogs hunting woolly mammoths:
http://siberiantimes.com/science/casestudy/features/did-dogs-help-drive-the-woolly-mammoth-to-extinction/
Nice write up Jess. Yes we love our dogs. And they love us. Thanks for sharing. God bless.
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