Becoming a Dog
Although we humans have had a relationship with dogs for thousands of years, many of us really don’t understand them and what motivates their behaviours. We can’t ask a dog how they feel or why they do something, so in the past we could only make assumptions about their motivations and feelings. Unfortunately, this led to a lot of misconceptions and often to the detriment of dogs.
Although dogs have been used for many years in research, these were generally more to do with issues relating to our health, biology, social development and learning. Sadly, most of these experiments didn’t end well for the dogs.
In the late 1990s things started to change with research beginning in the modern field of comparative dog cognition and behaviour. The term cognition simply means how we learn to understand the world around us through gaining knowledge and experiences which shape our behaviour and how we react in different situations.
Today dog cognition and behaviour have become an area for serious academic research, but the behaviours of any species have also been shaped by evolutionary processes; so let’s start with how we think dogs evolved and when they became humans’ companions.
In the past, we knew that there were several types of canids (the dog family) that evolved in many parts of the world but it was very difficult to find evidence of their ancestors and where they came from. Canids originally developed from a dog-like creature and over time they evolved into different species through adaptation to changing environments. For many years it was assumed that dogs evolved from wolves because of the similarities in their physical structures, but we didn’t know how to prove this. The bones of wolves and dogs look very similar, making it difficult to determine if archaeological finds, which were mostly just fragments, were from dogs or wolves and how old they were. With the development of carbon dating, scientists were able to determine the age of bones but not whether they were wolf or dog. It took the development of DNA sequencing to solve the mystery, and we now know that the modern dog’s ancestor is the Grey Wolf, a species that still exists in North America and Northern Europe though it too may have further adapted from its ancient ancestors.
So why did dogs start to evolve away from the Grey Wolf, how did they end up being our companions, and when did this occur?
The traditional theory of how wolves became dogs was that humans captured wolf puppies and domesticated them so that over time they turned into dogs. Certainly, wolf bones have been found in graves and middens of early humans but it is unclear if they lived with humans or were simply grave goods. As happens in the present day, it is likely that some humans did capture wolf cubs to keep as ‘pets’. The problem is that while you can tame a wolf, that is not the same as being domesticated. If a tame wolf has pups, they are born with all the traits of a wild wolf and they too require taming; in other words, their wild behaviour is coded in their DNA. The genetic make-up of domesticated animals has evolved to be coded for living beside humans, so they are born with a propensity to bond and be biddable with humans. Dogs were the first domesticated animals and chose to live beside humans, if not always within their homes. We still see this today with village dogs who will attach to one person or family but who choose to have the freedom of deciding to live semi-independently.
We now think that dogs themselves may have actually started the domestication process. Most Canids are opportunists taking food wherever they find it, and in populated areas, dingoes, coyotes and foxes will raid bins. Wolves are cautious animals so they avoid human populations, preferring to range over distances to hunt large prey. If needed they will also catch small mammals, or any other food that helps to sustain them, including stealing the kill of other predators. If really desperate, wolves will come close to human settlements seeking food. This is rare but many people believe that this is what started the wolf’s journey to becoming the domesticated dog.
The current theory, by contrast, says that humans have always created waste and some of that would be quite appealing to a hungry animal. It is thought that some wolves were brave enough to come near people for an easy meal and over time felt safe enough to hang around the camp or wherever there were humans. If those people didn’t feel threatened, they might see the wolves as beneficial in cleaning up around them and protecting them from other predators.
If wolves brought their offspring, then the next generations did the same, you begin to see wolves that feel comfortable being near humans. It’s well documented that offspring can inherit some emotional states from their parents which can be carried down through generations and even effect the coding of familial DNA thereby shaping new behaviours. It’s possible that, after a few generations, wolves started to incline toward domestication and seeking the company of humans.
We know that early people did indeed share their lives with dogs because of cave paintings depicting them with humans and because of dogs’ bones being found in grave sites. Because initially it wasn’t clear whether canid bones found in these graves were from wolves or dogs, determining when dogs evolved out of wolves and became domesticated was unclear. With new techniques in research, including DNA sequencing, researchers have been able to confirm that several sites did indeed contain dog bones. Further Radioactive Carbon Dating has been able to put dates to the finds and discovered that all the bones were from after the Last Glacial Maximum (LGM) that lasted from 19,000-26,000 years ago.
In 1962 the skull of a dog-like creature was found among the bones of many different animals in the Razboinichya Cave in the Altai Mountains of Serbia. The skull was nearly complete, in excellent condition and dated to 33,000 years ago, locating it before the LGM. At the time it was proposed that this animal was more like a dog than a wolf, but this was rejected as impossible because it was unlikely that the evolutionary process of going from wolf to dog had started prior to 19,000 years ago. Bones of a dog-like animal predating the LGM were also found in Goyet Cave in Belgium and were dated to 31,000 years ago.
Using DNA and comparing the skulls of both modern as well as ancient wolves and dogs, along with non-dog canids, it was found that it is likely that these animals were incipient dogs, in other words animals closer to being full dogs than wolves. However, DNA research shows no evidence that these animals were the ancestors of the modern dog because it doesn’t match modern dogs’ DNA. Other finds from further afield also suggests that dogs were evolving in many different places in the northern hemisphere. This is not uncommon in evolutionary development where a species distributed across large geographical areas can develop several different versions due to environmental differences. Current evidence suggests that the first transitions from wolf to dog did not actually survive the LGM.
A hundred years ago the remains of two humans, a man around 40 and woman around 20 and two dogs, one an older adult and one a puppy, were found in a grave in Bonn-Oberkassel in Germany from about 14,000 years ago (the early stone age). At first, the idea that these might be dog bones was not accepted. Instead, they were believed to be wolf bones and nothing other than grave goods. Now we know that these are indeed the bones of true, fully-evolved dogs and a very important early find. What is most exciting is that it appears that these animals were not grave goods but companions. The older dog had signs of arthritis and was likely to be unable to work but seems to have been well fed and cared for. The puppy had died from distemper and there was evidence that it was nursed through the illness until death. Surprisingly, it seems that both animals were looked after by their humans, indicating a bond had been forged between them and their dogs.
Today many more finds have emerged which show that dogs were domesticated prior to the emergence of settled agriculture, and that domestication was happening in many areas simultaneously. We know that dogs enter the New World alongside humans 12,000 to 14,000 years ago when there were probably large numbers already living in Eurasia including the Levant, Northern China and Eastern Russia. In 2021 a dog’s femur was discovered in Alaska dated to 10,150 years ago. Excavations at the Svaerdborg site in Demark have found three graves containing 8,000 years-old dog bones. Bones of dogs discovered in Arabia are also from this time. We are now sure that dogs have been living in human communities as domesticated animals since at least 10,000 years ago.
Today new discoveries continue to emerge from new excavations or by looking at previously-excavated bone collections, especially those once recorded as wolves. Who knows what the future may bring in our understanding of the relationship our ancestors had with dogs, but what we do know is that in the journey to the modern world, our species did so alongside dogs.
A 33,000-Year-Old Incipient Dog from the Altai Mountains of Siberia: Evidence of the Earliest Domestication Disrupted by the Last Glacial Maximum
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0022821
A new look at an old dog: Bonn-Oberkassel reconstructed
https://doi.org/10.1016/.jas.2018.01.004
https://www.psychologytoday.com/gb/blog/canine-corner/201802/is-emotional-attachment-dogs-modern-development
https://www.theverge.com/2017/7/18/15992572/dog-genetics-archaeology-fossils-evolution-domestication-wolves
Although dogs have been used for many years in research, these were generally more to do with issues relating to our health, biology, social development and learning. Sadly, most of these experiments didn’t end well for the dogs.
In the late 1990s things started to change with research beginning in the modern field of comparative dog cognition and behaviour. The term cognition simply means how we learn to understand the world around us through gaining knowledge and experiences which shape our behaviour and how we react in different situations.
Today dog cognition and behaviour have become an area for serious academic research, but the behaviours of any species have also been shaped by evolutionary processes; so let’s start with how we think dogs evolved and when they became humans’ companions.
In the past, we knew that there were several types of canids (the dog family) that evolved in many parts of the world but it was very difficult to find evidence of their ancestors and where they came from. Canids originally developed from a dog-like creature and over time they evolved into different species through adaptation to changing environments. For many years it was assumed that dogs evolved from wolves because of the similarities in their physical structures, but we didn’t know how to prove this. The bones of wolves and dogs look very similar, making it difficult to determine if archaeological finds, which were mostly just fragments, were from dogs or wolves and how old they were. With the development of carbon dating, scientists were able to determine the age of bones but not whether they were wolf or dog. It took the development of DNA sequencing to solve the mystery, and we now know that the modern dog’s ancestor is the Grey Wolf, a species that still exists in North America and Northern Europe though it too may have further adapted from its ancient ancestors.
So why did dogs start to evolve away from the Grey Wolf, how did they end up being our companions, and when did this occur?
The traditional theory of how wolves became dogs was that humans captured wolf puppies and domesticated them so that over time they turned into dogs. Certainly, wolf bones have been found in graves and middens of early humans but it is unclear if they lived with humans or were simply grave goods. As happens in the present day, it is likely that some humans did capture wolf cubs to keep as ‘pets’. The problem is that while you can tame a wolf, that is not the same as being domesticated. If a tame wolf has pups, they are born with all the traits of a wild wolf and they too require taming; in other words, their wild behaviour is coded in their DNA. The genetic make-up of domesticated animals has evolved to be coded for living beside humans, so they are born with a propensity to bond and be biddable with humans. Dogs were the first domesticated animals and chose to live beside humans, if not always within their homes. We still see this today with village dogs who will attach to one person or family but who choose to have the freedom of deciding to live semi-independently.
We now think that dogs themselves may have actually started the domestication process. Most Canids are opportunists taking food wherever they find it, and in populated areas, dingoes, coyotes and foxes will raid bins. Wolves are cautious animals so they avoid human populations, preferring to range over distances to hunt large prey. If needed they will also catch small mammals, or any other food that helps to sustain them, including stealing the kill of other predators. If really desperate, wolves will come close to human settlements seeking food. This is rare but many people believe that this is what started the wolf’s journey to becoming the domesticated dog.
The current theory, by contrast, says that humans have always created waste and some of that would be quite appealing to a hungry animal. It is thought that some wolves were brave enough to come near people for an easy meal and over time felt safe enough to hang around the camp or wherever there were humans. If those people didn’t feel threatened, they might see the wolves as beneficial in cleaning up around them and protecting them from other predators.
If wolves brought their offspring, then the next generations did the same, you begin to see wolves that feel comfortable being near humans. It’s well documented that offspring can inherit some emotional states from their parents which can be carried down through generations and even effect the coding of familial DNA thereby shaping new behaviours. It’s possible that, after a few generations, wolves started to incline toward domestication and seeking the company of humans.
We know that early people did indeed share their lives with dogs because of cave paintings depicting them with humans and because of dogs’ bones being found in grave sites. Because initially it wasn’t clear whether canid bones found in these graves were from wolves or dogs, determining when dogs evolved out of wolves and became domesticated was unclear. With new techniques in research, including DNA sequencing, researchers have been able to confirm that several sites did indeed contain dog bones. Further Radioactive Carbon Dating has been able to put dates to the finds and discovered that all the bones were from after the Last Glacial Maximum (LGM) that lasted from 19,000-26,000 years ago.
In 1962 the skull of a dog-like creature was found among the bones of many different animals in the Razboinichya Cave in the Altai Mountains of Serbia. The skull was nearly complete, in excellent condition and dated to 33,000 years ago, locating it before the LGM. At the time it was proposed that this animal was more like a dog than a wolf, but this was rejected as impossible because it was unlikely that the evolutionary process of going from wolf to dog had started prior to 19,000 years ago. Bones of a dog-like animal predating the LGM were also found in Goyet Cave in Belgium and were dated to 31,000 years ago.
Using DNA and comparing the skulls of both modern as well as ancient wolves and dogs, along with non-dog canids, it was found that it is likely that these animals were incipient dogs, in other words animals closer to being full dogs than wolves. However, DNA research shows no evidence that these animals were the ancestors of the modern dog because it doesn’t match modern dogs’ DNA. Other finds from further afield also suggests that dogs were evolving in many different places in the northern hemisphere. This is not uncommon in evolutionary development where a species distributed across large geographical areas can develop several different versions due to environmental differences. Current evidence suggests that the first transitions from wolf to dog did not actually survive the LGM.
A hundred years ago the remains of two humans, a man around 40 and woman around 20 and two dogs, one an older adult and one a puppy, were found in a grave in Bonn-Oberkassel in Germany from about 14,000 years ago (the early stone age). At first, the idea that these might be dog bones was not accepted. Instead, they were believed to be wolf bones and nothing other than grave goods. Now we know that these are indeed the bones of true, fully-evolved dogs and a very important early find. What is most exciting is that it appears that these animals were not grave goods but companions. The older dog had signs of arthritis and was likely to be unable to work but seems to have been well fed and cared for. The puppy had died from distemper and there was evidence that it was nursed through the illness until death. Surprisingly, it seems that both animals were looked after by their humans, indicating a bond had been forged between them and their dogs.
Today many more finds have emerged which show that dogs were domesticated prior to the emergence of settled agriculture, and that domestication was happening in many areas simultaneously. We know that dogs enter the New World alongside humans 12,000 to 14,000 years ago when there were probably large numbers already living in Eurasia including the Levant, Northern China and Eastern Russia. In 2021 a dog’s femur was discovered in Alaska dated to 10,150 years ago. Excavations at the Svaerdborg site in Demark have found three graves containing 8,000 years-old dog bones. Bones of dogs discovered in Arabia are also from this time. We are now sure that dogs have been living in human communities as domesticated animals since at least 10,000 years ago.
Today new discoveries continue to emerge from new excavations or by looking at previously-excavated bone collections, especially those once recorded as wolves. Who knows what the future may bring in our understanding of the relationship our ancestors had with dogs, but what we do know is that in the journey to the modern world, our species did so alongside dogs.
A 33,000-Year-Old Incipient Dog from the Altai Mountains of Siberia: Evidence of the Earliest Domestication Disrupted by the Last Glacial Maximum
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0022821
A new look at an old dog: Bonn-Oberkassel reconstructed
https://doi.org/10.1016/.jas.2018.01.004
https://www.psychologytoday.com/gb/blog/canine-corner/201802/is-emotional-attachment-dogs-modern-development
https://www.theverge.com/2017/7/18/15992572/dog-genetics-archaeology-fossils-evolution-domestication-wolves
