I have to dedicate the first post to the very name of the blog – Evolving Canine.
One of my favorite branches of biology is evolution. And I will show you how the world of dogs would be a much better place if we were guided by its principles.
The exponents in the text (1,3) indicate the ordinal number of the source in the reference list at the end of the text, which means that the given information is based on sources rather than the author’s opinion.
What is evolution?
Evolution is the change in the frequency of genes within a population over time (1). Natural selection, mutations, recombination, and genetic drift are the main mechanisms that cause these changes (1). These mechanisms create new combinations of genes within a population, giving animals different traits. Natural selection then “selects” those traits that help animals survive and reproduce better (1), while less useful or harmful traits gradually disappear. These life traits, that increase likelihood of survival or contribute to successful reproduction are called adaptations (1). In this way, evolution leads to the gradual adaptation of species to their environment. To simplify, and to connect with a term that you have probably heard in the dog world – evolution makes animals “more functional”.
The story of evolution
Most people think of dinosaurs, fossils, and Neanderthals when they hear the word evolution. But evolution is still around today and it’s still shaping species.
Take vertebrates, for example (Fig. 1). The first vertebrates originated in the sea, but competition for food, space, and mates quickly increased. Now imagine if some fish figured out how to move to land! They would have plenty of room to themselves, new food sources, and safety from predators. That’s exactly what happened, and we got amphibians. Now, amphibians were still partialy tied to the water. They started life in the water (think tadpoles) and breathed through moist skin.
Later, some amphibians evolved into reptiles – animals with scales that protect them from drying out. The “big reptiles” (dinosaurs) dominated the land, but limited space and resources spurred new adaptations. Some reptiles evolved into birds, some into mammals. These groups solved a key problem for reptiles: independence from environmental temperature, thanks to a metabolism that generates heat from food. Both groups then adapted to a variety of environments: seas, freshwater systems, the sky (birds and mammals fly), polar regions (only birds and mammals live at the poles), forests, grasslands, and eventually cities. Evolution provides different solutions. In humans, it was intelligence – an investment in the brain, not in physical fitness.
This story simplifies the evolutionary process: in reality it’s actually pure trial and error. There were many genetic variations, but only those that were more functional than others survived.
*Note: I will refer to “environment” many times in this post; in ecology, this is actually called“ecological niche”. The concept of ecological niche is extremely complex and I do not want to use it without a detailed explanation. But for the purposes of this text, “environment” is more than enough.*
The evolution of dogs
How did wolves evolve into dogs? Scientists are still working to answer this question.
Most believe that wolves had to go through a process called domestication to become dogs. Domestication is the process through which wild plants or animals undergo genetic and phenotypic changes under human influence, adapting to human environments and needs.
There are several theories of wolf domestication, but two stand out (2-4).
The first hypothesis suggests that wolves domesticated themselves (2–4). As humans began to live a sedentary life, they created a new habitat for wolves: one with abundant food scraps. Just as fish once migrated to land, wolves migrated into human settlements.
The second theory holds that humans purposefully “stole” wolf pups and gradually domesticated them (2-4). In this process, it is necessary to mention one more detail:
The dog did not originate from the wolf. Wait, what?
The dog evolved from a common ancestor of dogs and wolves (5-7) (Fig. 2, Fig. 3). Sarah Marshall-Pescini, a scientist who studies dog behavior, suggests in her work that the “protowolf” (as I will call it) was different from today’s wolf (6,7). That is, it probably had some predispositions that today’s wolves do not have, which enabled the development of dogs. It is possible that they were less fearful, had different feeding or reproductive strategies. This assumption disrupts some of the explanations for domestication because we compare wolves and dogs in research, when in fact we should be comparing protowolves and dogs.
Now, let’s go back to the evolutionary story of dogs.
Figure 3. Main steps in the evolution of dogs according to the schematic illustration presented by Dr. Ádám Miklósi in his book Dog Behaviour, Evolution, and Cognition (Chapter 6.2.1). I added the protowolf population and the last step based on my own judgment; therefore, this reflects my opinion, not a scientific source.
1. The first step is the process of protodomestication, where initial transitional populations of protowolves emerge. The first adaptations to the “human” (urban) environment begin. At this stage, some would describe these canids synanthropes (3) – a species that lives in close association with humans and human settlements, using resources that humans create or modify, but without necessarily being fully domesticated. Such animals began to adapt to a sedentary lifestyle and a scavenger diet. One adaptation of proto-wolves to these new food sources was the emergence of genes for starch digestion, which appeared approximately 11,000–16,000 years ago (10).
2. In the second step, initial populations of dogs emerge. Here, populations begin to be shaped by human selection (3,7). Dogs that show less fear and aggression, greater cognitive abilities, and greater sociability have an advantage. Along with natural selection, human selection also begins.
3. In the next step, the beginning of the population of “feral/village” dogs is formed. This population still exists today and is genetically significantly different from purebred dogs and crossbreeds (8,9).
4. From the initial population of dogs, along with feral/village dogs, working dogs begin to develop. We call these populations “landraces”. A landrace is a locally developed population of dogs that arose spontaneously, through long-term adaptation to a specific environment and human needs, without systematic or standardized breeding. The main landrace groups are hounds, herding dogs, hunting dogs, sheepdogs and sled dogs.
The ideal and most common example is the livestock guardian dog. These dogs evolved in adaptation to pastoral communities (11). One key adaptation was the complete loss of predatory drive and the predatory sequence (11). Dogs that did not attack livestock were more valuable to shepherds. Such dogs were favored, for example, by being fed more, and therefore survived and passed on their genes. At the same time, they developed a guarding instinct.
And so the traditional “breeds” were created – Kangal, Akbash, Tornjak, Šarplaninac, Caucasian Shepherd… The breeds are intentionally in quotation marks because landraces are NOT actually breeds. In these populations, there was no planned breeding selection before mating (there was no pre-zygotic selection (11)). The dogs mated freely within the population, and only those with the necessary characteristics for survival and work persisted (post-zygotic selection). It was only in the mid-20th century that the FCI recognized these breeds, separating certain individuals from the population, closing the registry, and thereby closing the population.
Here I want to emphasize once again the selective pressures and genetic diversity of the first working dogs. It was a combination of human selection – humans favored dogs with the right behavior – and natural selection, where only functional, healthy dogs survived.
What does this mean in practice? If a dog showed good working behavior, but suffered from chronic allergies or hip dysplasia, it simply did not survive. Imagine a Kangal with open wounds from grass allergies or a lame dog with bad hips, trying to work in mud, rain, and while fighting wolves – such cases simply did not occur. A dog with a genetic predisposition to skeletal issues or a weak immune system lost its advantage over healthier dogs and was eliminated from the population. This may sound cruel, but it is exactly how nature works: in the first generations, it removes disease predispositions, preventing them from developing in the first place.
In addition, these populations were genetically diverse (12), because they were open. If a dog had the desired characteristics but was not “of the same breed”, it could still mate and pass on genes. Registration was not required – only functional behavior and health were important.
5. I modified the last step slightly from the source. I updated it to better suit the current state of the dog community.
In addition to wild/village dogs, I have separated 4 more categories:
Purebred dogs
FCI (Fédération Cynologique Internationale) started recognizing breeds at the beginning of the 20th century. The process of recognition is long, and ends with the closing of the initial population (founding stock). The stock of genes that exists at that time is the largest, and after the registry is closed, genes can no longer be added – they can only be lost.
One of the goals of this international organization was to preserve traditional breeds and their roles. However, unsustainable selection criteria were adopted – a written standard focused primarily on appearance, while health and behavior were sidelined. This was not intentional; of course, everyone wants healthy, well-behaved dogs. Nevertheless, the selection rules were built on the wrong foundations.
How does this affect evolution? Purebred dogs are subjected to human, pre-zygotic selection: desired characteristics, as defined by the breed standard, are selected before mating (before the formation of the zygote). This selection is excellent for obtaining specialized and extreme forms – show dogs come in a variety of colors, shapes and coat textures. However, it reduces genetic diversity (14-16) because reproduction is limited to selected individuals, which leads to the accumulation of hereditary diseases (16-19). The problem is that health is difficult to assess (e.g. hip dysplasia (13)). Although responsible breeders test for known diseases (e.g. full genetic panels cover about 300 conditions), this is negligible compared to the actual number of diseases for which we do not yet know the genetic basis.
In nature, this is handled differently, as in landrace dogs – resources go only to resistant individuals, and the rest simply do not survive.
Behavioral selection is also problematic in purebred populations. Apart from a few basic tests for certain breeds (depending on the rules of the national kennel club), there is no mandatory test of the dogs’ true working abilities in a working environment.
Figure 4. Note that all lions are the same color. Nature produces the best uniformity of appearance, adapted to function (in this case, camouflage). In the center are representatives of the same dog breed, uniform in appearance, which is the goal of selection. The image on the right shows dogs of different breeds and appearances, but of the same species (unlike lions). In dogs, there is significantly greater appearance diversity within the species.
(Image sources https://vcaweb.org/about-vizslas/vizsla-breed-history/ , https://www.kinship.com/dog-behavior/are-dog-parks-good-socialization)
Sporting and working crossbreeds, outcrossed dogs
Behavioral selection was particularly problematic in sports and working circles. For a dog to be successful in sports or work, it must have the desired behavior. In addition, one of the requirements is health – a dog with health problems cannot compete with others. This already sounds like a biological rule, doesn’t it? And indeed, it is a form of competition based on functionality.
In some breeds, a division occurred into working and show lines (they are geneticaly distinct (20)), and in others, crossbreeding with other breeds began. At the same time, new “environments” appeared. Traditional dog jobs (sheep herding, herding cattle, sledding, hunting) are slowly disappearing, while new jobs (protection, service dogs, SAR) and sports (agility, frisbee, bitework, canicross, bikejoring, flyball, etc.) are emerging. These new “environments” also require new adaptations – which simply did not exist in the past. This is human selection, only with a different goal than the FCI standard. However, it is important to recognize that natural selection does not operate here, which means that health can also be compromised. A classic example is the “popular sire effect” (21): when a successful dog or line is exceling in a sport, they are preferentially used in breeding, which reduces genetic diversity.
It is also worth mentioning dogs involved in outcross projects as examples of planned and meaningful crossbreeding. These projects are designed to improve the health of breeds that are extremely genetically compromised. Examples include the Cavalier King Charles Spaniel, Doberman Pinscher, Pug, Norwegian Lundehund. The health of these breeds is so poor that the first priority is to increase genetic diversity. First, another breed is introduced to expand the genetic base (outcross), and then backcrossed to the desired standard. The main difference between sporting/working crossbreeds and outcross projects lies in their purpose: sporting and working crossbreeds are created to serve new functions, with increased genetic diversity serving only as a prerequisite for functionality; in outcross projects, the goal is to preserve the existing purpose while improving health.
It is also worth mentioning another purpose – dogs for companionship. Often forgotten, because professionals mostly have working dogs, but in fact it is the most sought-after form today. Most people are looking for a pet (although they may not be aware of it). Unfortunately, the health of these dogs in many purebred populations is seriously impaired (e.g. Cavalier King Charles Spaniel). We should not forget that these dogs should also be bred for a purpose and functionality: to open up populations, increase genetic diversity and improve health.
Unplanned mixed breeds (modern breed mixes)
I have singled out unplanned mixed breeds as a separate group because they exist – and in large numbers. They are genetically more diverse than purebred dogs (22,23), are generally healthier (15,18), but can still carry deleterious alleles (18,23,24). They are not intended for working purposes. The population is open, but a large part of the animals do not actually actively contribute to the population because they are neutered (reproductively isolated). I want to separate these dogs from irresponsible breeding (“backyard breeding”). Both types of mixed breeds are often found in shelters, but this does not mean that they are comparable and the same.
These dogs can be excellent pets, especially when they have a weaker working drive, and can be a good solution for many families. They come from a variety of situations – from accidental matings to abandoned dogs (these are not feral/village dogs) and often end up in poor living conditions. Shelters are full of them and they are the real victims of our breeding. Although most of them are neutered, their number is constantly increasing because irresponsible owners ensure a constant influx of dogs.
Some call these dogs unstable and “genetic disasters”, but they do not take into account that most of these dogs have not had any socialization, they are often first dogs, their owners are mostly civilians (they are not “professionals”, they have a lower level of knowledge about dogs), they do not have the support of a sports club and a breed club and are left to their own devices.
Irresponsible breeding “backyard bred dogs”
I have nothing positive to say about these “breeders”, especially about breeding “exotic” dogs, except that they started public education on responsible breeding. These dogs may come from open populations, but they are not genetically diverse or healthy. The main selection pressure is money. These breeders deliberately breed conformation extremes, mate closely related dogs, do not test for diseases and actively undermine the health of the dogs. Also, in order to create exotic hybrids, they crossbreed breeds with incompatible instincts, which leads to unstable temperaments (and this is intentional).
The future?
With this text, I wanted to give you a closer look at how dogs came to be, but from the perspective of adaptation and selection.
Much of the evolution of dogs was shaped by a combination of human and natural selection, while populations were open and dogs were functional. Only in modern times has selection been almost exclusively human. Closed populations were introduced in a relatively short period of history, and the consequences for dog health are already significant. Functionality-driven selection is the main tool for improving health. Purebred breeding is not the only way to create a dog with a purpose. This is something I rarely hear in the dog world, and many disagree with it.
And there are reasons for this disagreement. The FCI was right in one aspect – breeders need to be given clear guidelines and rules. Breeders are the ones who carry out both prezygotic and postzygotic selection, and the quality of dogs depends on them. And it is not enough for one breeder to maintain a high standard, because his dogs are just a speck in the population. The entire community must strive for the same. And this is often not possible without an umbrella organization and rules (unfortunately, not everyone has the same interests).
Most importantly, owners must seek these standards and criteria. A simple rule of supply and demand.
Due to incompatible adaptations and the environment in which dogs live, many can end up with behavioral problems. You have probably heard that dogs need to be given an “outlet” for their breed specific behaviors. Their adaptations should make sense, that was the goal of the entire evolution. However, since most of us live in cities, this can be difficult. That is why it is important to research what kind of dog you have and what its needs are. What would its ideal environment look like and how much you are able to provide it? You need to make sure that your lifestyle suits the purpose of the dog. I am not just referring to purebreds and working dogs here – many mixed breeds are ideal pets, and perhaps that is exactly the purpose you need. They have remnants of some working habits, but they take on the characteristics of a “general” domesticated animal.
Because as you can see, years of evolution have shaped such behaviors. This part of a dog’s character is genetic – it’s not all about “how you raise them”.
And that’s where we get to the point of the name of this blog – Evolving Canine. Dogs are completely dependent on us: from breeding, training, nutrition and welfare – it’s up to us to “evolve”. We need to learn every day, because we shape our dogs’ lives.
It all started with a mutt
This blog was created to improve dogs’ lives, promote critical thinking, and provide accurate information, written from the perspective of a biologist..
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Reference list:
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