How did the first dogs appear, from the domestication of the wolf? Let’s see.
The dog is man’s best friend, but he hasn’t always been. At some point in prehistoric times, humans and wild wolves established a bond that would strengthen for thousands of years.
This phenomenon is the domestication of the dog, which has involved its progressive evolution from the wild primal ferocious wolves to all the breeds of canines that we know today.
The scientific community has tried to find out how, when and where this process occurred for the first time, raising various theories based on the genetic findings of different fossils and modern races. Let’s see it next.
When did the domestication of the dog begin?
The domestication of the dog was a gradual process, of which the scientific community has not yet clarified where, when and how it happened. What is known is that modern Canis lupus familiaris is a descendant of a primal wolf, as is the case with gray wolves. At some point in evolutionary history, those wolves and humanity’s best friends parted ways, establishing themselves as two different species. This event had to occur between 15,000 and 40,000 years ago.
Scientists have tried to find out how an animal as dangerous and ferocious as the wolf could, at some point in its existence, end up being the most friendly species that can be found in many homes. Many genetic studies have been done throughout the globe, analyzing modern breeds and skeletal remains that have been found in Asia and Europe to establish when the domestication of the dog occurred.
The problem is that the matter could not be clarified. The dates proposed by the scientific community vary widely, and the fact that it is not clear if it was in Asia, Europe or somewhere in the middle does not help. It has been agreed to accept that the first domesticated wolves must have lived between 15,000 and 40,000 years ago.
Did it happen multiple times over the years?
One of the most shocking recent discoveries has been that the dog was attempted to be domesticated on more than one occasion. Several scientists have analyzed the mitochondrial DNA of 59 different dog remains that lived in Europe, ranging in age from 3,000 years (times close to Ancient Rome) to 14,000 years. In addition, the entire genome of a dog that lived 4,800 years ago that was buried near a prehistoric monument in Ireland could be analyzed.
The genome obtained from these dogs has been compared with that of modern breeds of their congeners and with wolves, suggesting that the dogs were domesticated in Asia about 14,000 years ago. Their lineages were divided in two, in the period that would go from 14,000 years to 6,400 years ago, forming the great populations: one in the Far East and the other Eurasian.
But, despite this, other fossils older than those have been found in Europe. This finding had led to positions, such as Thalmann’s group, that dogs emerged in Europe and spread from there. However, others have found that this branch, which is supposed to have been the first dogs in history, ended up becoming extinct at some point, being replaced by the Eurasian breeds.
From these findings it can be extracted that, in reality, the investigations that had ensured that the dogs had arisen in Europe or Asia were, certainly, the reason. That is to say, it is not that today’s dogs descend from all those primitive populations, but it is true that the domestication of the dog occurred in various places at different times in history.
In addition, this allows to have a more open mind, since it allows to accept the idea that there were more than two domestications, fighting against somewhat recalcitrant positions that had been established in the scientific community regarding this matter, especially among European experts.
How did they become our best friends?
The questions of when and where dogs were domesticated have yet to be fully answered, but a third question still remains: how did prehistoric man manage to domesticate the big bad wolf?
One of the theories considered is that of defenselessness. A wounded wolf was found by some prehistoric human who, instead of killing it, took care of it. The wolf, grateful for the treatment, began to be more tame, accepting the food of his new friend and, soon, he began to have a more protective and friendly attitude towards the human being, a behavior that had to be transferred to other congeners. But this explanation is too simplistic and doesn’t have much scientific backing.
Another theory holds that prehistoric humans managed to capture baby wolves, keep them as pets, and gradually domesticate them. This event could have occurred more or less during the agricultural boom, some 10,000 years ago. The oldest fossils of what appear to be dogs date back 14,000 years, but fossils almost twice as old have also been found of apparently something resembling a dog or something that was no longer a primeval wolf.
Thanks to the most recent research in genetics, it has been suggested that the date of the domestication of the dog must have occurred earlier, supporting a new theory. It shouldn’t have happened because a wounded wolf became tame, or because pups were kidnapped.
The most plausible explanation is that the primal wolves, as with any other species, showed personality differences, with some being more sympathetic and others more aggressive. The friendliest ones were closer to humans, without hurting them, which must have awakened a less defensive attitude on the part of the prehistorics.
Seeing that the beasts were beneficial for their protection, especially for predators of fields and crops, humans, little by little, were accepting the company of wolves and, eventually, domesticated them.
This domestication involved changes in appearance, making them more “adorable”, in the opinion of Brian Hare, one of the expert scientists on the subject. The wolves began to develop more human-friendly characteristics, characteristics that must have occurred within a few generations, such as drooping ears, longer chest fur, curly tails, and the sensation of smiling when breathing through their mouths.
But it is not just the physical that has changed over the generations. Wolves’ own behavior became increasingly geared toward satisfying human beings. They became even more agreeable, focusing their attention on their new owners and acquiring a behavior very oriented to provide protection to humans.
Genetic evidence for the theory
A study by evolutionist Bridgett M. vonHoldt of Princeton University offered genetic evidence to support this theory. Dogs, compared to wolves, show higher levels of motivation when looking for interactions with humans. This would show that there is a genetic tendency, shaped by the passage of thousands of years, to promote beneficial behavior towards the human species.
Von Holdt saw that there are regions in the genome of dogs and wolves that are shared, only that there are modifications in dogs. These modifications in the regions but of the human genome cause Williams-Beuren syndrome, a condition in which the person is extremely trusting and very friendly.
How much have these animals changed?
Although the exact origins of how the long-lasting relationship between humans and dogs was formed, it has been discovered how each species has changed. Differences between dogs, such as pugs, dachshunds, or poodles are very obvious compared to wolves. But, in addition to this, and as we were already commenting, there are personality differences and, what is most striking, their link with human beings and their hormonal response.
Research has found that the bond that has been favored between dogs and humans, learning to work with humans, has impaired teamwork between dogs. Their lifestyle and pack mentality have been reduced compared to wolves, even catching wild dogs. However, they seem to have developed the ability to solve problems by asking their human owners for help.
An example of this is the experimentation on problem solving between dogs and wolves. For example, if a problem is set to be solved, such as opening a box through a puzzle, dogs and wolves respond differently. As a general rule, wolves will try to find a solution through trial and error. Instead, dogs first stare at what they have to solve and then turn around looking into the eyes of their owner, as if asking for help. This is a very interesting interspecific social behavior that can hardly be observed in other species.
And speaking of looking into my eyes. The brains of dogs and humans have been shown to be in sync. If a dog and its human owner look into each other’s eyes, their brains begin to secrete oxytocin, a hormone linked to maternal love and trust. Oxytocin is not unique to dogs and humans, since it is found in other species and has a very important function in establishing bonds between the mother and her offspring or with peers, but the case of dogs with humans is something that is not known. has found in other species.
Of course, the way, the time and the place in which the first human-dog bond was established has been of great importance in the history of the evolution of mankind. A life without dogs is unthinkable, something that could well have happened if their great-great-grandparents (to save us millions of “great-greats”) had not had the great idea of approaching a group of hunter-gatherers. What would life be like without dogs? Of course, we give thanks to the capriciousness of evolution that they did so.
- Thalmann, O., Wahlberg, N. (2013) Complete Mitochondrial Genomes of Ancient Canids Suggest a European Origin of Domestic Dogs. Science. DOI: 10.1126 / science.1243650.
- B vonHoldt, J Pollinger, D Earl, et al. (2012) Identification of recent hybridization between gray wolves and domesticated dogs by SNP genotyping. Mammalian Genome 12 (1-2), 80-88
- M Thompson, B vonHoldt, S Horvath, M Pellegrini (2017) An epigenetic aging clock for dogs and wolves. Aging 9 (3), 1055-1068.
- MacLean, EL, et al. (2017) “Individual differences in cooperative communicative skills are more similar between dogs and humans than chimpanzees.” Animal Behavior, vol. 126, pp. 41–51. Scopus, doi: 10.1016 / j.anbehav.2017.01.005.