If you ask Google "how dogs were domesticated" you will get over half a million 'relevant' hits.
So you might think the domestication process is well known and widely accepted.
And you would be wrong!
There are many things we don't know but lets start with the bits we do know.
- Dogs are not descended from modern day wolves, instead the dog and wolf both come from a common ancestor
- All our dogs are descended from a wolf ancestor - so no other canine species (e.g. wild dogs, cayotes, jackals) were ever successfully domesticated
- Humans had 'domestic' dogs at least 14,000 years ago which is around 4,000 years before agriculture became a thing
- Humans and their dogs migrated together into new territories (e.g. when land bridges allowed)
- Our dogs genes were altered with the advent and spread of agriculture and can be seen today with an increased frequency of genes that allow digestion of starchy foods found in dogs living in areas where agriculture became an established way of life.
Ok, so far so good. Now for the interesting bit - the stuff we don't know:
We don't know when domestication occurred with some geneticists suggest the process could have started as early as 135,000 years ago! Most scientists consider this to be way too early, with most estimates dating from 27,000 years to 40,000 years ago. Which is still a huge difference of opinion.
We don't know how these wolves were domesticated. You will find lots of theories or you might like to think of them as stories we tell ourselves. Here are just a few:
An ancestral wolf pack learned to hang out at the periphery of human settlements for discarded food and became less fearful and 'tamer' as a result - this is known as the 'scavenger theory'. Littering may have been a problem even then.
The wolf ancestor was the alpha predator at that time but in winter the human tribes may have had more lean meat than they could eat. Humans aren't great at digesting low quality lean meat and this surplus could have been actively fed to wolves, though why a human population would do this is questionable.
Human tribes take in orphaned wolf puppies and raise them, but would such puppies stay with the humans or, more likely re-enter the wild and compete (probably more effectively) with the humans that raised them (at least in the earliest stages of domestication).
Both humans and wolves interact regularly as they scavenge off the same carcass - though watching nature documentaries it is difficult to see how that would result in co-operation.
We don't know why wolves became dogs. What was in it for the humans, or the dogs. As I mentioned earlier, our relationship with dogs definitely started before agriculture and a long time before we had any other domesticated animals. This means that they couldn't have offered security (protecting the crop either plant or animal). At this time we would have been small nomadic tribes and any wolf ancestor living around humans would have been extra mouths to feed and potentially dangerous to the children, elderly and vulnerable tribe members.
We don't know if domestication was one single event that then spread or occurred in multiple locations at different times.
So, to go back to the beginning, wolves and dogs originate from a common wolf ancestor. This is important because, to my knowledge we have never domesticated any modern wolf species, or isolated populations. We have tame(r) wolves but they are not truly domesticated. At this point it is important to highlight that there are some important difference between domesticated dogs and wolves which makes the domestication story harder to understand.
So what do I think?
Around 40,000 years ago, Europe and Asia (the most likely locations for domestication) was a very cold, very dry and very dusty which could have reduced the quantity and quality of the vegetation. The herbivorous animals would have struggled to find enough food and this would mean the carnivores and omnivores would have restricted, poorer quality protein available. Food resources were likely to be scarce and fiercely contested.
I would assume that, whilst humans didn't have permanent settlements (which come along with agriculture) they would have had a winter base and been nomadic in the summer. For this strategy to work humans would have been storing food in the summer and autumn to allow for survival over the long, cold and dark winters.
Could humans have had surplus food in the winter to feed a predator who posed a risk to the group? Or could they have seen that wolves would be looking for scarce food resources in the winter and would be hanging around the edges of the winter encampment anyway. Humans at this time would likely be in tune with their surroundings and would be able to identify wolf packs and individual wolves as either regular visitors or new arrivals. Would they have decided that if wolves were hanging around anyway it would be better to build a relationship with an established pack. If a pack was 'encouraged' to stay around - but not too close to the encampment - would they then defend the camp as part of their territory?
Wolves are territorial, social creatures and would recognise specific humans. So I can imagine that over many generations the established wolf pack could associate with the human tribe as an extension of the group. Tolerating each others company, and recognising and even interacting at an individual animal level. Wolves, like humans have different personalities and so some humans and some wolves might form closer ties.
Could this then mean that even in the summer months when the humans were hunting and foraging they were followed by the wolves in order to maintain the whole group. It would not be long before humans would benefit from the better senses of their canine companions when out in more exposed, harder to defend nomadic settlements. They may even start to share each others kills.
As the two species interact more closely their relationship would likely change, with humans starting to identify and relate to and prefer individual wolves. True domestication is then possible as humans select the wolves/dogs they like the traits of.
I believe that the two species initially came together in a partnership with each offering something beneficial to the other. This is important when we look at domestic dogs and in particular our pet dogs because a relationship is only healthy when both parties gain from the arrangement.
Dogs have been part of the human story for so long that I think it would be difficult to estimate what they, as a species, have and continue to bring to the arrangement.
Though it is not possible to prove that dogs have changed the way we have adapted and developed it is equally impossible to rule it out. Could our relationship with dogs have meant that humans as a species have narrower sensory ranges - less sense of smell, relatively poor night vision? It would be arrogant in the extreme to assume that a partnership lasting this long would only influence the genes and behaviour of one of the species.
So to summarise, our dogs descend from an ancestral wolf and through a series of environmental and social pressures they were domesticated.
Our dogs are unique, the only animal to be domesticated before agriculture.
They are amazing, not just the furry friend taking over your furniture, but the millions and millions of street and village dogs that live alongside us too.
They are incredibly successful as a species and are found wherever you find humans. They actively seek out human interaction and both we and they appear to significantly benefit from the arrangement.
So how does this all relate to our daily lives and how I work?
Our dogs are part of our lives and it is therefore easy to forget just how incredible their evolutionary journey has been and how incredibly lucky we are to have such a wonderful partnership.
But a healthy relationship requires both species to benefit. For this to happen there must be a mutual level of trust and respect as well as effective communication. This would have been key on the domestication journey, but it is as relevant today as it was thousands of years ago.
In order to treat a dog in pain or to help an owner train their dog I need to continually work on the trust, respect and communication of both the owner and their dog. I need to quickly and effectively build trust so that the dog will allow me to assess and work with them. I need to respect them and their boundaries, treat them with consideration and kindness. I need to be really clear in communicating my intentions so that the dogs can relax and take on the treatment or training. It helps, of course that our dogs have spent the last 40,000 years or so getting to know us and want to work with us.
Arendt, M., Cairns, K., Ballard, J. et al. Diet adaptation in dog reflects spread of prehistoric agriculture. Heredity 117, 301–306 (2016). https://doi.org/10.1038/hdy.2016.48
Briggs, H (2017) How did dogs become our best friends? New evidence https://www.bbc.co.uk/news/science-environment-40638584
Handwerk, B (2018) Smithsonian.com How Accurate Is Alpha’s Theory of Dog Domestication? https://www.smithsonianmag.com/science-nature/how-wolves-really-became-dogs-180970014/
Hare, B & Woods, V (2013) Opinion: We Didn’t Domesticate Dogs. They Domesticated Us.
Scientists argue that friendly wolves sought out humans. https://www.nationalgeographic.com/animals/article/130302-dog-domestic-evolution-science-wolf-wolves-human
Lazzaroni1, M, et al (2020) The Effect of Domestication and Experience on the Social Interaction of Dogs and Wolves With a Human Companion, Frontiers in Psychology, Vol 11, Page 785 https://doi.org/10.3389/fpsyg.2020.00785
Marshall, M (2021) Humans may have domesticated doges by accident by sharing excess meat - https://www.newscientist.com/article/2264329-humans-may-have-domesticated-dogs-by-accident-by-sharing-excess-meat/
Tiny Verse (2019) A Brief History of Dogs - How We Domesticated Dogs https://www.youtube.com/watch?v=xmw3jRqS9oQ