Canine Evolution and Domestication
‘It’s just a dog’: what an infuriating, non-sensical utterance about dogs. In fact, what is a dog?
By studying evolution and domestication, we deepen our understanding of the common ancestry and interconnectedness of all living beings on earth, their adaptation and diversification over time to occupy different niches and habitats. We see the complex web of relationships between species, the mechanisms that drive genetic mutations to respond to environmental changes, and how new species arise.
Through domestication, species have altered their genetic makeup and behavior. Through natural relaxed selection and later artificial selection wild ancestors have developed into domesticated forms that are more useful to humans and can coexist with them without fear. This process of domestication has played a crucial role in human history, providing us with food and companionship.
By recognizing this shared ancestry and interconnectedness, we can develop a more respectful and empathetic relationship with the natural world and strive for a more harmonious coexistence with other species.
Before Darwin, the prevailing view was that all living organisms were created by God in their present forms and that they remained unchanged throughout history. Darwin's theory of evolution by natural selection challenged this idea by proposing that species change over time through the process of natural selection, by which individuals with traits that are better suited to their environment are more likely to survive and reproduce, passing on their advantageous traits to their offspring. Over time, this process can lead to the emergence of new species.
What was even more ground-breaking about Darwin's theory was the idea that all living organisms share a common ancestor. Life on Earth likely originated in water; English comparative anatomist of the 19th century Sir Richard Owen discovered that many creatures with limbs share a similar bone pattern known as the "tetrapod limb" and consists of one bone (the humerus in the upper arm), two bones (the radius and ulna in the lower arm), lots of blobs (the carpals in the wrist), and five digits (the metacarpals and phalanges in the hand).[1] This basic structure is seen in all tetrapods (Amphibians, reptiles (including dinosaurs and birds) and mammals and is thought to have evolved in a common ancestor.
Evolution means adaptation for survival: in a world where creatures are arranged in a prey/predator pyramid structure, to survive you either got bigger or faster, you either camouflaged or left altogether. So, gradually we went from fish with fins that had no similarities with limbs, to fish that could do ‘push-ups’ like Tiktaalik[2], to amphibians, reptiles, birds, and mammals, including us. We have a similar number of genes, our embryos at conception are nearly undistinguishable; the timing and intensity by which key genes turn on or off will determine who gets paws or hands![3]
Darwin understood that creatures evolved but could not tell us how. The study of DNA, present in all living creatures, got us there. This long molecule spiralling along a double Helix works as a code that can be arranged in infinite sequences, each one determining how living creatures appear and live. Diversification over time happens through DNA changes at conception (embryos’ DNA is the mix of the father’s and mother’s DNA), via mutations (as DNA copies itself when cells divide, mutations occur causing minute changes) and through epigenetics[4]. Creatures whose mutations favour survival in a certain environment live and pass on their useful genes. Those whose mutations prove unhelpful, die out.
Based on this common ancestry, behaviourists and trainers’ initial concern should be to prepare the human client for a perspective of respectful, equal playing field. Over the millennia animals’ autonomic nervous system developed following the same design to regulate organs and body functions (breathing, digestion, blood pressure etc), to store and release energy to allow movement. The autonomic nervous system, through a subconscious surveillance system called neuroception, scans for signs of safety and danger; if danger is detected it moves us either into a dorsal vagal collapse or shutdown (a branch of the parasympathetic nervous system)[5] or into a fight or flight response (sympathetic nervous system).[6] Around 200 million years ago, mammals developed the ventral vagus (the second branch of the parasympathetic system) allowing us to feel safe and connected. As each new system emerged, it joined the older system rather than replacing it.[7] The way we perceive the world through neuroception will determine how we feel and ultimately how we behave. We will be able to either connect, move away (into either fight, flight), or shut down.[8] In addressing dogs’ behaviour through this lens, we look for the emotions that drive it. We can see how we share the same circuitries of motivation, emotion, and learning.
When we speak of domestication we distinguish between:
long-term domestication (the evolution from a far ancestor to which the dog is as far removed as we are from ours – possibly Grey wolf for the dog and Sahelanthropus tchadensis for humans).[9] A commonly accepted theory about the domestication of dogs is that as humans transitioned from a hunter-gatherer lifestyle to one based on agriculture, they began to live in permanent settlements and generate large amounts of food waste. This waste attracted wolves, who began to scavenge in and around the settlements. Over time, in a process of relaxed natural selection (scavenging was less dangerous than hunting) some wolves became less fearful of humans and more willing to live near them. Wolves that were less fearful and more cooperative with humans were more likely to receive food and protection, leading to increased survival and reproduction (a process known as relaxed natural selection). [10]
short-term domestication (As the relationship between humans and wolves evolved, humans began to selectively breed dogs for certain traits, such as herding, hunting, or guarding. This artificial selection process led to the development of the many different dog breeds we see today).
individual domestication (related to the personal history and journey of the individual dog).
Applied ethologist Kim Brophey [11] has created a beautiful image that incorporates all three forms of domestications which must be considered when analysing canine behaviour:
The antecedent in the operant conditioning three-term ABC contingency cannot be reduced to the immediate event but must extend to four further elements: Learning (phylogeny and ontogeny), Environment (changing habitats and niches and their impact on dogs’ lives, choices or lack thereof), Genetics (DNA through evolution, long/short and individual domestication) and Self (biological state of the individual animal, individual traits, personality, personal likes and dislikes etc).
Most dogs are captive animals, whose every aspect of life is dependent on their carers’ choices. It would be important to educate owners on the 5 freedoms of animal welfare (freedom from hunger and thirst, from discomfort, from pain/injury/disease, to express normal behaviour and from fear and distress), and how they are strictly linked to the mental wellbeing of animals. Should their mental state be negatively affected, this could result in physical changes, such as through a physiological stress response (increase in heart rate, blood pressure, and cortisol levels). These changes can have a negative impact on the animal's physical health. Top of the agenda would be to strive for a healthy coexistence and a strong relationship based on mutual trust, love, empathy, and compassion.[JG8] Especially in relation to the need to express normal biological behaviour, I would also question whether the fact that these behaviours may make the owner’s life difficult is a good enough reason to change them. In many cases, we end up pathologizing perfectly normal behaviours that respond to an instinctive need of the animal: here, rather than working on behavioural change, I would concentrate on behavioural management and finding acceptable outlets for that behaviour. The preventative step would be to help perspective owners to choose dogs that most fits their lifestyle and environment.
Explaining canine body language would help client read the emotions that drives their dogs’ behaviours. Dogs are very good at observing us (their life depends on it), we must do the same in reverse. Reading the subtleness of canine communication expressed through all body parts working together (not just singling out individual ones) will help not only in interspecies but also intraspecies[12] communication.
Finally, owners would benefit from exposure to evolution and domestication concepts as it will steer them away from old fashioned, scientifically debunked theories[13] that are at the base of punishment-based training techniques. [14]Today, we know that we can achieve much better results whilst empowering dogs to try things out without fear of failing or punishment. More and more trainers use force-free, positive, LIMA (Least Intrusive Minimal Aversive) teaching methods based on proven learning mechanisms that apply to all life forms (classical conditioning, operant conditioning), and use positive reinforcement and personalised motivation to maximise the learning outcome.
To conclude, an outline of a case I am working on with initial suggestions:
Footnotes
[1] The differences between creatures lie in the differences in the shapes and sizes of the bones and the numbers of blobs, fingers, and toes. Shubin, N. (2009) in Your inner fish: The amazing discovery of our 375-million-year-old ancestor. London: Penguin, p. 31.
[2] Tiktaalik had a shoulder, elbow, and wrist composed of the same bones as an upper arm, forearm, and wrist in a human. Shubin, p39.
[3] What Darwin Never Knew - Embryos (2016) YouTube. YouTube. Available at: https://www.youtube.com/watch?v=4a_vdzYU69U
[4] Whilst DNA is set at birth and cannot be changed or affected by the environment, the epigenome can switch genomes on or off depending on which ones are best for the animal in a set environment. A genetic trait could fade away over generations if the genome related to it is not switched on for long enough. Gutteridge, S. (2018) in Inspiring resilience in fearful and Reactive Dogs. Independently published, p. 22.
[5] 500 million years ago a prehistoric fish called placoderm used the branch of the parasympathetic system we know as dorsal vagal. Dana, D. (2021) in Anchored: How to befriend your nervous system using polyvagal theory. Boulder, CO: Sounds True, p. 26.
[6] Around 400 million years ago, the sympathetic nervous system emerged in another now extinct fish called an acanthodian. Dana, p.27.
[7] Dana, p.27.
[8] Dana, p21-22.
[9] Sahelanthropus tchadensis (2022) The Smithsonian Institution's Human Origins Program. Available at: https://humanorigins.si.edu/evidence/human-fossils/species/sahelanthropus-tchadensis
[10] Gutteridge, p.18
[11] Brophey, K. (2018) Meet your dog: The game-changing guide for understanding your dog's behavior. San Francisco: Chronicle Books.
[12] I think there are similarities between the living conditions of those unrelated captive wolves forced to live together for studying purposes and those of our modern captive dogs in crowded urban environments. Post pandemic there has been a massive increase in dog ownership; dogs are forced to share crowded spaces and often face a lack of choice (first and foremost the choice to not interact). This can lead to increased stress and anxiety for dogs, which can manifest in aggressive responses. It's important for owners to be mindful of this and recognize that dogs are individuals and may not always want to interact with other dogs, even if they are friendly and well-socialized. Dogs' boundaries should be respected. If all owners managed their dogs as if they were so called ‘reactive’, it would easier to avoid forced interactions among unfamiliar dogs. This could prevent confrontations and reduce stress for all dogs.
[13] In 1947, animal behaviourist Rudolf Shenkel carried out observational studies on captive wolves that were not family related and therefore not reflective of the natural dynamic of a wolf pack in the wild. The wolves in captivity naturally showed tension amongst each other, and their antagonistic behaviours were taken as normal in the species and then transferred onto dogs, as wolves’ descendants. Gutteridge, p.16
[14] These were based on concepts of dominance and constant struggle for the alpha role in the pack. Around the 80’s, American biologist David Mech conducted other studies that highlighted the flaws of earlier theories. Wolves pack showed to be much more like human families, where naturally only father and mother would breed (rather than fighting their offspring for the alpha role), whilst other family members would cooperate to maximise the chance of survival.
Bibliography
Brophey, K. (2018) Meet your dog: The game-changing guide for understanding your dog's behavior. San Francisco: Chronicle Books.
Dana, D. (2021) in Anchored: How to befriend your nervous system using polyvagal theory. Boulder, CO: Sounds True.
Gutteridge, S. (2018) in Inspiring resilience in fearful and Reactive Dogs. Independently published.
Sahelanthropus tchadensis (2022) The Smithsonian Institution's Human Origins Program. Available at: https://humanorigins.si.edu/evidence/human-fossils/species/sahelanthropus-tchadensis
Shubin, N. (2009) in Your inner fish: The amazing discovery of our 375-million-year-old ancestor. London: Penguin
What Darwin Never Knew - Embryos (2016) YouTube. YouTube. Available at: https://www.youtube.com/watch?v=4a_vdzYU69U
