News: Guest Posts
An international group of scientists proposes dual domestication from wolves.
Among the many hotly debated topics related to the appearance of dogs in the lives of humans is how often and where it first occurred. In their landmark 1997 paper on dog origins, Robert K. Wayne, Carles Vilá, and their colleagues made the case for multiple origins, but many other students of dog evolution, including Peter Savolainen, a co-author on that paper, have repeatedly and strongly argued for a single place of origin.
In this week’s Science magazine (June 3, 2016) [the article is available here, gratis], Laurent Frantz of Oxford University’s ancient dog program, writing for more than a score of his colleagues from institutions around the world, presents the case for dual domestication of Paleolithic wolves in Western Eurasia and Eastern Asia. According to this hypothesis, a now extinct ancestral wolf split into at least two genetically distinct populations on opposite sides of the Eurasian continent where they encountered and joined forces with humans to become dogs.
Frantz and his coauthors pin much of their argument on analysis and comparison of the fully sequenced genome of a 4,800- year old dog unearthed at Newgrange, Ireland, to other ancient and modern dogs and modern wolves. They found it retained “a degree of ancestry” different from modern dogs or modern wolves. Using that and other evidence the researchers argue that the most comprehensive model for the appearance of the dog involves at least two domestication events 15,000 or more years ago. Frantz writes: “The eastern dog population then dispersed westward alongside humans at some point between 6,400 and 14,000 years ago, into Western Europe (10,11, 20), where they partially replaced an indigenous Paleolithic dog population. Our hypothesis reconciles previous studies that have suggested that domestic dogs originated either in East Asia (9, 19) or in Europe (7).”
I asked Greger Larson, co-director of the Oxford project and corresponding author on the paper, just what were the boundaries of “Western Eurasia,” comprised apparently of Europe and the Middle East, and “Eastern Asia?” He answered in an email that the boundaries were left deliberately vague because where wolves became dogs remains unknown, like the date itself.
In Science, Frantz writes: [W]e calculated the divergence time between two modern Russian wolves used in the study and the modern dogs to be 60,000 to 20,000 years ago.” The first number puts the dog in the time when Neanderthal was still the big kid on the European block, raising the possibility that Neanderthal had protodogs or that early modern humans came to Europe with dogs or soon allied with wolves. Either of the first two prospects must have set off alarms in some circles for Frantz cautions that those dates should not be taken as “a time frame for domestication” because the wolves they used may not have been “closely related to the population(s) that gave rise to dogs.”
Fundamentally, this paper is at once a bold attempt to come up with a workable hypothesis to explain the appearance of the dog in human affairs and a tentative step into troubled waters. Left unanswered are virtually all outstanding questions regarding the who, what, when, where, and why of the transformation of wolves to dogs. Geographically all it does is exclude Central Asia. Whether it does so wrongly may depend on how you define Central Asia geographically.
What makes it bold and radical even is the suggestion that early humans and wolves could have gotten together wherever and whenever they met on the trail of the big game they were following. There are many reasons for that including similar social and familial cultures, but humans and wolves could have joined forces to have become more successful hunters. We learn from Wolves on the Hunt: The Behavior of Wolves Hunting Prey by L. David Mech, Douglas W. Smith, and Daniel R. MacNulty (Chicago, 2016) that while wolves appear excellent at finding and trailing game, they are not very good at making the kill, succeeding perhaps half the time. It is dangerous work at which humans with their weapons excel.
Imagine the scene: Human hunters locate wolves on the hunt by watching ravens who are known to follow them. Human hunters move in for the kill and take as many animals as they can. If smart, they might share immediately with the wolves. If not, the wolves might consume what the humans do not carry off or follow them back to their encampment to take what they can.
The rest is a tale of accommodation through socialization—the ability to bond with another being—and all that entails.
This article originally appeared in Psychology Today's Dog's Best Friend, used with permission.
We may think our dog wIll take a treat from any hand that offers it, but a new study by a team of Japanese researchers suggests that may not be the case. Primates engage in something called “social eavesdropping”— essentially, making judgments about others based on interactions that don’t directly affect their own interests. This study tested dogs’ ability to do the same by setting up situations in which the dogs’ owners asked for help in opening a box and were assisted (helper scenario), rejected (non-helper scenario), or ignored (control scenario) as the dogs looked on. After these interchanges, when the dogs were offered treats, they took them randomly from Helper and Control “strangers” but were biased against non-helpers. According to Kazuo Fujita, professor of comparative cognition at Kyoto university and one of the study’s authors, the ability to socially and emotionally evaluate others “is one of the key factors in building a highly collaborative society.” So, another step in the process of understanding how Canis lupus became familiaris: like humans, dogs are able to pick up clues about who to trust and who to avoid.
Good Dog: Behavior & Training
Technology facilitates communication
What if dogs could talk? Specifically, what if service dogs and bomb-sniffing dogs could talk? Associate Professor Melody Moore Jackson at Georgia Tech, and a team that includes Professor Thad Starner, Research Scientist Clint Zeagler, and Jackson’s Border Collie Sky, are developing technology that allows dogs to say anything we give them the capability of saying. They’ve called their project FIDO, which is short for “Facilitating Interactions for Dogs with Occupations.”
They developed a vest with sensors on it that dogs can activate to communicate. The vest can play a message or send a text to a smart phone. From a training perspective, it’s a basic system—dogs are trained to hit specific sensors in response to certain cues. So, if asked which toy a person is holding, the dog can hit a sensor that plays a message that says, “That is the Frisbee®” or “That is the ball.” That is a cool trick, but the real genius of this vest is the variety of messages dogs can send.
For example, a service dog for a hearing-impaired person might hit a sensor in response to an alarm that sends a text saying, “I heard the alarm,” and a different sensor in response to the doorbell so that the message reads, “I heard the doorbell.” Many hearing impaired dogs lead their person to the source of a sound, such as a crying baby. This vest adds to the benefits of a service dog because it would also allow a person to be notified of a sound that is not reachable, such as a tornado siren. Just like distinguishing between the ball and the Frisbee®, telling these sounds apart is a type of discrimination task, and is the basis for many of the ways that this vest can be used.
For example, detection dogs are usually trained to bark if they find what they are looking for, perhaps a drug or an explosive. Although dogs are often trained to search for multiple types of drugs or explosives, they are limited in their ability to communicate the details of their finds to their handlers. It can make a big difference to everyone’s safety if the dog can let a handler know that the bomb is a stable type or an unstable one that needs careful handling. This vest can allow a dog to share more specific information.
This group developed a vest that allows a dog who has found anyone trapped after a natural disaster to activate a sensor with a message for that person to hear. The message lets the trapped individual know that help is on the way. Work is underway to develop a vest that allows a dog to activate a sensor that sends GPS coordinates to a handler. This allows the handler to join the dog, who does not have to leave the person who has been found. That could be lifesaving for a child who is hiding or for a person who is unable to move for whatever reason.
Similar technology could benefit people with any number of health problems. Imagine that a person with epilepsy has a seizure and the service dog has been trained to activate a sensor in response to that situation. The activation of the sensor would result in a call to 911 and also send a message to a family member. The message would include GPS coordinates and say, “My person had a seizure and 911 has been contacted.”
The possibilities of this technology are limitless. A dog could be trained to hit a sensor in response to someone saying, “Get help.” When that sensor is hit, a recording plays so anyone nearby hears, “My owner needs your attention. Please follow me.” This technology is very exciting because it allows dogs to communicate specific helpful information to people. The beauty of the design is that it is relatively easy to teach dogs with a solid base of training to activate sensors in response to specific cues. These vests represent a wonderful blending of solid dog training with new technology to increase the ability of dogs and people to accomplish a variety of tasks together.
Culture: Science & History
What can archeology tells us about the “connection” origins.
Studies of prehistoric dog burials have been making splashy headlines lately. Although the popular press would have us believe that these finds are proof of the affectionate relationship our ancestors had with dogs, the unifying theory that gives meaning to burial patterns remains elusive because ancient people left no written record.
What little we know about dogs’ social roles in antiquity is a patchy mosaic of information derived from physical analysis of bones excavated from gravesites. The accuracy of this mosaic has been further complicated by archaeologists’ long-standing difficulty with reliably distinguishing between wolves and dogs, not only because the two animals look similar, but also because changes in morphology during the early stages of domestication were subtle.
However, in 1986, zooarchaeologist Darcy Morey, now adjunct professor in anthropological sciences at Virginia’s Radford University, developed a statistical equation to more accurately identify dissimilarities between skulls. A decade later, geneticists were able to extricate even more conclusive information from DNA. Then, in a landmark paper published in 1999 in the Journal of Heredity, geneticists Carles Vilà, Jesus Maldonado and Robert Wayne suggested that the first domestication event occurred more than 100,000 years earlier than dog burial remains suggested. This marked the beginning of a decades-long trend that all but excluded archaeology and other academic disciplines from the equation.
Morey—and later, Greger Larson, evolutionary biologist in Durham University’s Department of Archaeology in the UK—challenged the exclusive use of DNA analysis to identify the time and place of the first domestication event. They advocated a return to a cross-discipline approach that included traditional archaeology, DNA analysis, isotope geochemistry and radiocarbon dating in the context of environmental sciences such as paleoclimatology and biogeography.
Robert Losey, associate professor of anthropology at the University of Alberta, is among the scholars who agree with this approach. “When the genetic information can be integrated with information on dogs’ diets, diseases, activity patterns and archaeological context, we get a much more complex and informative picture of people’s emotional and day-to-day lives with their animals than we can through genetics alone.”
Siberia’s Lake Baikal, the largest and oldest freshwater lake in the world, is known for its well-preserved Middle Holocene (3,000- to 9,000-year-old) hunter-gatherer cemeteries, which attract scientists studying how social and environmental pressures influence long-term cultural change. Leading a team of researchers from various disciplines, Losey analyzed numerous Lake Baikal sites containing human, dog and wolf remains dating back 5,000 to 8,000 years; the team’s findings were published in 2011 in the Journal of Anthropological Archaeology.
As he explained, “What I tried to do in my study was to approach these dog skeletons just like we would a human skeleton. We applied a suite of analyses in order to tease out the interesting and relevant details of their lives. The best way to fully understand the domestication of dogs is to use as many forms of evidence as possible, and to employ a wide range of specialists.” Their interpretive model was partly based on ethnographic records of indigenous groups from across the northern hemisphere. For example, many northern people, who have an animistic understanding of their world, strongly believe that animals, plants and inanimate objects possess souls.
Using stable isotope analysis, researchers determined that dog and human diets were the same. In comparison, a wolf found buried in the same area had foraged on large game, a diet different than that of local people. Some dogs were buried with artifacts the dog would have used or been familiar with during its life: a decorative collar-like pendant made with red-deer teeth, a round ball-like stone, spoons, antlers and other implements.
Bone-wear suggested that the dogs had worked alongside people, likely as transport animals hauling heavy loads. Some had recovered from injuries that would have required special care. People and dogs were buried near one another in the same cemetery, and in some cases, were buried together (in one instance, a man was buried with two dogs, one on either side). Analysis of the dogs’ skeletons revealed a resemblance to modern-day Siberian Huskies, although they would have been larger. Genetic work on the specimens confirmed an ancestral link to our modern dogs.
According to Losey, “I think what we are really looking at is a set of relationships between people and dogs, and to study relationships, we need to try to understand the life histories of animals, not just their evolutionary history.”
Putting all of the small parts together, the researchers painted a big picture. They suggested that ancient indigenous people considered some dogs to be very special. Unlike the majority of simpler animals, whose spirits collectively recycled after death, these dogs were thought to be like humans, with powerful and unique souls that required mortuary rites similar to those of deceased people.
This special treatment was necessary for both dogs and humans so that their souls could return in new individuals. Losey added, “I think the act of treating a dog as a human upon its death indicates that people knew it had a soul, and that the mortuary rites it received were meant to ensure that this soul was properly cared for. These practices also clearly indicate that people had close emotional bonds with some of their dogs, and perhaps mourned their loss like they did [the loss of] their own family members.”
Waves of Proto-domestication
Although romanticized images of digs in the shadows of ancient civilizations continue to feed the popular notion of archaeology, a more accurate but less dramatic scene would have scientists in white lab coats conducting microscopic analyses of polymorphic nucleotides extracted from bone remnants stored for many decades on museum shelves. Indeed, bones unearthed long ago have proven to be quite revelatory. The most unexpected discoveries regarding the human/dog relationship are based on analyses of materials extracted from canid bones excavated, catalogued and archived in 1873 and 1884, respectively.
The oldest skull, which dates to 31,700 years ago, was found at Belgium’s Goyet Cave. Another from a site in Predmosti in the Czech Republic proved to be about 27,000 years old. One skull from the Predmosti site had a mammoth bone fragment in its mouth. Does it indicate that a special connection had developed between people and dogs as far back as 30,000 years ago? Archaeologist Mietje Germonpré of the Royal Belgium Institute of Natural Sciences—lead author of the two papers describing the 2008 and 2012 research results—said, “I believe that the dog skull with the bone between its teeth suggests some sort of ritual treatment. The position of the bone fragment in the mouth suggests that it was inserted between the incisors of the dog post-mortem.” The ethnographic record indicates that placing body parts between the teeth of dead carnivores was a common practice in many cultures. Exactly why remains open to speculation.
Paleoanthropologist Pat Shipman, who has written extensively on the evolutionary impact of the human/animal connection, suggested that the mammoth bone points to a cross-species alliance that may have developed even earlier—one that might account for the success of our early ancestors. She hypothesized that proto-dogs, like those found at the Predmosti site and at Goyet, cooperated with humans in a symbiotic hunting partnership that could account for the significant and abrupt increase in the number of animals found at mammoth kill-sites dating as far back as perhaps 45,000 years. The initial domestication of dogs may have been accidental, but once humans realized the value of these living “tools,” they began to refine them for increasingly specialized purposes.
In a separate study, a group of researchers led by Ole Thalmann examined ancient DNA of Eurasian dogs (the Predmosti dogs had not been genotyped) along with others, and came up with some surprising results. Separated by only a few thousand miles and a few thousand years, the ancient dogs were not related to each other, nor were they related to modern dogs. In addition, none of the lines survived, which suggests that domestication experienced many starts and stops in different regions with different wolf populations. Scientists speculated that the last ice age, which began about 26,000 years ago, might have contributed to this stutter-step process. They also found that living dogs are more closely related to ancient, extinct wolves than they are to modern wolves.
If domestic dogs somehow catastrophically died out, would we have the natural resources needed to recreate them? In Shipman’s opinion, “The answer is both no and yes. If dogs disappeared, they probably couldn’t re-evolve from the wolves we have now. But those extinct wolves evolved into contemporary wolves, and canids in general have a huge amount of variability in their genomes, which is why we have so many different types of dogs today. If by ‘dogs,’ you mean a highly variable canid that can live with and cooperate with humans, then I think the answer is yes. Would it be the same dog as today? We can’t be sure.”
Laid to Rest with Care
In the past two decades, archaeologists have unearthed the remains of about 1,400 dogs buried 2,500 years ago on prime ocean-view real estate in ancient Ashkelon, today a thriving city located on the Mediterranean Sea, 30 minutes from Tel Aviv. The dog burials spanned a period of eight decades. Carefully positioned alone in shallow pits, the dogs’ bodies were placed on their sides, legs flexed, tails gently tucked around their hind legs. Ranging in age from newborn through elderly, they appear to have died of natural causes.
Ashkelon is only one of thousands of ancient dog-burial sites scattered across the globe, and its large number of burials raises the question, “How many dogs were buried in antiquity?” The answer is, “We’ll never know.” Throughout prehistory, people mostly disposed of bodies, human and non-human, in untraceable ways; they sent them floating down rivers or buried them in shallow earthen graves—reverent practices that lost them to the ages.
In addition, dog burials were so common that they are field sites’ most overlooked artifacts. In her 2009 manual, A Practical Guide to In Situ Dog Remains for the Field Archaeologist, Susan Crockford, adjunct professor at the University of Victoria in Canada who has worked with dog remains for more than 20 years, maintains that far more dog burials are encountered than are ever mentioned in archaeological site reports. Workers aren’t properly trained to recognize dog remains, nor do most understand the history of dogs and their significant contribution to the human story. Consequently, much of what we could have learned about the human/dog connection has been lost forever.
Furthermore, scientists can’t develop statistical estimations because it’s unclear whether or not dog burials are representative of the total dog population. However, by calculating the timing of genetic bottlenecks, Thalmann and his colleagues suggested that ancient dog populations paralleled the trajectory of human population growth. Dog numbers increased steadily until about 5,000 years ago, then abruptly declined, followed by a sharp increase 2,500 years later. Even if their calculations are proven accurate, whether (and why) certain dogs were selected for burial while others were not remains unclear.
The first comprehensive review of dog burial studies, “Burying key evidence: the social bond between dogs and people,” by Darcy Morey, published in the Journal of Archaeological Science (2006), put the documented cases and site locations in perspective. Written for a scholarly audience but with enough humanity to appeal to lay readers, the paper brought new attention to a topic of inherently widespread interest. Given that so many burials are untraceable and others are uncertain, why even suggest a total?
Professor Morey said, “Depending on circumstances, for a given site, I think it’s possible to suggest how many were buried, at least in that place.” In a later book, Dogs: Domestication and the Development of a Social Bond, Morey included an appendix that inventoried dog burials, including totals as known from specific places. “But,” he added, “given frequent uncertainties, I think in general that suggesting combined totals is fraught with problems.”
As companions and helpers, dogs hold a special place in our hearts, and increasingly, as our equals in relation to our place in the collective physical world. Mary Elizabeth Thurston, author of The Lost History of the Canine Race, anthropologist and historian for Hartsdale Pet Cemetery in Westchester, N.Y., said, “Fifteen years ago, about 55 percent of the public believed pets deserve mortuary rites in death. Today, the number is much higher.”
Thurston also noted an uptick in the number of people who wanted to be laid to rest with their animal companion, either by arranging for their own cremated remains to be buried with the pet, or for the cremated remains of that animal to be interred with them. “When animals fill an innate need for companionship as either surrogate children or life partners, they become truly indispensible in the eyes of their human caretakers. The desire to be together is understandable. The grief felt at the death of that pet is profound, and people want to accord their animals a measure of respectful remembrance in death, just as [they] would any other family member. However, we can’t assume that ancient people, who left no written records, held our same modern sensibilities.”
Canine remains in ancient human burial pits more often indicate that the dog was part of an offering, sacrifice or spiritual ritual rather than a companion. Thurston suggested that the ancient interment of single animals with grave goods, especially things that the dog used in life, along with evidence that shows the dog died of natural causes, might suggest an affectionate relationship and the belief that the animal had a soul—that, like people, it would need these things on the “other side” for a good life.”
In “Peru’s Mummy Dogs,” writer Roger Atwood noted that in 2006, Sonia Guillén, archaeologist at the Maliqui Center in Ilo, Peru, reported that her team had discovered 40 dogs buried about 1,000 years ago in separate plots alongside the remains of what were probably their owners. The discovery was unusual in that the dogs were interred with items that look like toys and food. As Guillén, who studies Peru’s Chiribaya culture (which pre-dated the Incas), told the press, “We have found that in all the cemeteries, always, in between the human tombs, there are others dedicated to the dogs, full-grown and puppies. They have their own graves, and in some cases they are buried with blankets and food.” Guillén, who suspects that the dogs may be direct ancestors of the companion and working dogs who populate the village today, is collecting DNA for future study.
Most human/dog burials occurred 5,000 to 8,000 years ago in hunter-gatherer societies and disappeared with the beginning of the agrarian era. But their absence doesn’t equate to a lack of an affectionate human/dog connection. At the Lake Baikal site, when pastoralists inhabited the area beginning about 5,000 years ago, they did not bury dogs, at least not in areas where archaeologists might find them. According to Robert Losey, “The difference between the pastoralists and the hunter-gatherers living in this area of Siberia is that the hunter-gatherers buried some of their dogs in cemeteries used otherwise for the human dead. The pastoralists do not appear to have done this.
“Over the past few years, my colleagues and I have interviewed local Buryat people, who are descended from some of these early pastoralists, about their dogs, and they clearly have a deep respect for [them], and do bury some of them. However, they are not considered non-human persons with individual souls, and in the local belief systems, are not spiritually equivalent with humans. So, they cannot be buried in local cemeteries. The best dogs, and the most loved ones, are given burial rites in some cases, but these tend to be elsewhere—on the tops of hills or mountains, for example. Some folks even recounted that they left pieces of meat in the graves with the dogs—food for them in the afterlife.”
As long as dogs have existed, they have been deliberately buried in every region they inhabited. Moreover, dogs have been buried more often than any other animal: singly, with other dogs, near people and with people. This ancient practice was a global phenomenon, one that crossed nearly all cultural boundaries. Precisely why dogs were buried may never be clearly understood, but the universality of the practice suggests it may be embedded in the human psyche and accordingly, is a fundamental part of the human/dog connection.
For in-depth information on sources cited click here.
Good Dog: Behavior & Training
The short answer is that it depends
Behaviorists, including myself, have cautioned people for years about hugging dogs because dogs don’t like it. One of the most easy-to-find types of photos shows a jubilant person hugging a dog who is miserable to some degree or another. It is very common for dogs to dislike being hugged, but for people to love hugging them. It should come as no surprise that members of two different species have different preferences.
Of course, there are exceptions, which I’ll get to later, but the general pattern is that the majority of dogs are not as crazy about hugs as people are. It’s a subject that deserves more research, which is why I was so pleased to read a recent post by Stanley Coren, Ph.D, called The Data Says “Don’t Hug the Dog!”
Coren viewed 250 random photos on the internet of people hugging dogs. For each photo, he determined whether the dog fit one of three categories: 1) the dog appeared stressed or anxious, 2) the dog appeared relaxed and at ease, and 3) the dog appeared neutral or ambiguous.
Signs of stress can be tongue-flicking, ears down, face averted, eyes showing “half-moons” of white, furrowed brows, tightly closed mouth, rigid facial muscles, and furrowed brows. Dogs who are relaxed and happy tend to have open mouths, relaxed facial muscles, and no signs of stress. Coren only included photos in which the dog’s face was visible and in which no other obvious stressor was present. (Other obvious causes of stress included things such as being picked up while being hugged.)
Coren found that of the 250 dogs, 204 (81.6%) of the dogs showed one or more signs of stress, discomfort or anxiety, 27 (10.8%) of the dogs showed either neutral of ambiguous reactions to being hugged and 19 (7.6%) seemed comfortable with being hugged. From these data, Coren concluded that it makes sense to recommend that humans refrain from hugging dogs, but instead save their hugs for other humans.
His results don't surprise me at all. I’m inclined to agree with his suggestion that these pictures might even underestimate dogs' dislike for hugging (at 80%) because pictures posted are selected by people who are presumably posting photos to show their love for and bond with their dogs. Coren points out that hey are not overly likely to choose photos with the most blatant signs of distress in the dogs, at least not if they recognize those signs.
Coren’s suggestion that it is not a good idea to hug dogs has many professionals nodding their heads in agreement, but many people have also objected to it. Most of the objections take the form of people saying that their dogs love being hugged. This is to be expected by anyone who has spent time discussing this contentious subject, which includes me. It comes up in my work because of the large number of dog bites that happen when a person is hugging a dog. It’s a very common context for bites to people, especially to children.
Over the years, I have had countless clients—in private consultations and in classes—as well as friends, neighbors, cousins etc. who swear that their dogs do like being hugged. However, whenever they hug their dogs to show me, I see dogs who show no signs that they like it. Most show anxiety and discomfort. Some tolerate it, but I would at best call their reactions neutral. With a few, I can't tell if they don't mind or if they have just learned that this is their lot in life and have stopped reacting. Either way, I do not see dogs who are convincingly happy about it. So, my personal experience is generally in line with what Coren found in his research, though he did see more dogs who were comfortable with hugging than I have.
His finding that there are a minority of dogs who were comfortable with hugs will be reassuring to many people who are confident that their dogs do love being hugged. I would encourage anyone who feels that their dogs fit into this category to make an effort to be sure. Observe your dog carefully during a hug to check for signs of anxiety, stress of discomfort. Sadly, I’m convinced that not everyone who is certain that the dog they love to hug also loves being hugged is corrrect. We have a situation here that is comparable to the well-known fact that most people think that they are above-average drivers. Similarly, almost all parents think that they are in that rare minority of people who do not regularly embarrass their teenagers. Obviously, in these examples, some people are right, but just as obviously, some people are wrong. The math just doesn’t allow any alternative conclusion.
That said, there are exceptions, as I mentioned before. There are people who I respect very much who are dog experts and who have told me that they have dogs who enjoy hugs. I also know of a few people who have consciously worked to condition their dogs to hugs, sometimes with the goal of being able to take a charming photo of themselves hugging the dog. If you hug a behaviorally healthy, non-aggressive dog and then offer him a piece of chicken, and do that repeatedly (by which I mean hundreds of times) you are likely to teach him to be happy about hugs. If one of my great-aunts, who shall remain nameless, had given me a brownie (or five dollars) every time she pinched my cheeks, I probably would have felt more cheerful about it, too.
Though many people assert that their dogs love to be hugged, most qualify that by noting that the dogs love hugs from family members and close friends, but not from strangers. There is general agreement that hugging unfamiliar dogs is a risky proposition and I’ve heard no objections to the general advice that this behavior should be avoided. However, there have been many criticisms of the idea that we shouldn’t hug our dogs at all. I think as general advice, it makes sense, but because there are exceptions, perhaps it is wise to state it as, “When in doubt, don’t hug a dog.” Then, we all need to be very careful about how we eliminate the doubt if we choose to hug a dog.
How we hug a dog can make a difference. For example, I see dogs who like to snuggle and seem happy to lean up against a person who then has one arm around them, but that's not what’s usually meant by a hug. Still, I have seen people refer to it as a hug when draping an arm around a dog who leans in closer, enjoying the attention and physical contact. It’s more common for a hug to be putting arms around a dog’s neck and hanging on. Kids are especially likely to hug in this way, and I generally feel sorry for dogs when I see this happen. Many dogs make no attempts to escape, and if you don’t carefully observe the signs of distress, it would be easy to assume that they are okay with it, but often they look miserable. A gentler hug that is not as long, as tight or as high up on the neck may be easier for dogs to accept, though I know of no study that investigates that possibility.
When considering exactly what a hug is, I think of dogs who appear to hug people, because I think there are dogs who like to do so. I've seen some tall dogs such as Leonbergers, Newfoundlands, Great Danes and large Labs or Shepherds who stand on their back legs and put their front paws on the shoulders of a person. They seem quite happy to hug people in this Marmaduke style. Of course, though that looks like a hug, too, it's not at all the same experience as dogs who receive hugs by having a human wrap her arms around them.
I'm really glad that Coren collected these data because this is an issue that we talk about a lot in the canine world but data are sparse. The blog post detailing his findings has led to many responses and conversations about whether or not dogs enjoy being hugged, and that exchange of ideas is valuable.
I'm know that many readers love hugging their dogs and people are always sad about the possibility that not all canines share our human love for hugs. I personally wish that all dogs loved being hugged, and not only because that would mean fewer dog bites and distraught families. I also say that because I love to hug dogs, which is why the dogs in my life have to tolerate it on occasion. I try not to overdo it, and I certainly don’t do it when the dogs are busy with some other activity or not in a good mood, but I do not totally abstain from hugging them either.
The main point is that “It depends” is a fair answer to the question of whether dogs enjoy being hugged or dislike it. Not only does it depend on the individual dog, it also depends on who is doing the hugging, the situation and on what is meant by a hug.
What have you observed about your dog’s response to being hugged?
Wellness: Healthy Living
Arizona genetics researchers are taking the unusual step of asking for dog lovers’ help in fighting a mysterious, potentially lethal infection that plagues both dog and man.
They are looking for dogs to be registered and potentially to have their DNA collected to help combat valley fever, a fungus-based disease once confined to the Southwest desert but is now spreading across the country.
Valley fever can be triggered by inhalation of just a handful of spores of a particular fungus. People, dogs and cats are susceptible to the illness that was once believed to occur only in Arizona and California. The disease is not contagious and is not spread from species to species.
The risk for valley fever increases as climates get drier, say California State University, Bakersfield researchers. Warmer temperatures and less rain basically kill off the fungus’ competitors for nutrients and thereby creating an ideal growing environment for the infection-causing fungus.
Valley fever is now being reported in states such as Michigan, Ohio and Minnesota, which never used to see the condition. And the states that typically see the condition are reporting more and more cases: The number of Valley Fever reports is increasing in more than a third of California’s counties, putting more dogs at risk for a disease that can lead to lameness, extreme weight loss and coma.
When Charlie, a 75-pound Chocolate Lab, started coughing, it didn’t set off any alarms. But then he developed a fever and was diagnosed as having kennel cough, which can be easily treated by antibiotics and steroids. Then the symptoms returned and again it was misdiagnosed as pneumonia. More than two months passed before Charlie was given the correct medication; the delay in a correct diagnosis lessens his chances for a full recovery.
Charlie now spends most of his time sleeping off the effects of valley fever, instead of being his normal playful self.
There is no cure for valley fever. Currently treatments focus on helping dogs beat the symptoms. Vet bills can mount up since a dog may have to get medication for up to eighteen months; in some severe cases, a dog may be on medicine for the rest of his life. It is estimated that Arizona dog lovers spend $60 million per year in caring for dogs with valley fever.
Seeing the increase in valley fever cases across the U.S., Phoenix-based Translational Genomics Research Institute (TGen) researchers are now asking for dog people to take a brief online survey about their pet’s breed, health history and lifestyle. After the survey, the dog may be selected to give a saliva sample.
Then after the swabbing is done, researchers will look for differences in the genes of dogs who are sick compared to dogs who show signs of exposure to valley fever but who aren’t sick.
“In certain dogs, a minor infection can progress to severe disease, and the reasons for this are unknown,” said Dr. Bridget Barker, assistant professor and head of TGen’s Northern Arizona Center for Valley Fever Research in Flagstaff, Ariz.
This information would be used to help develop new therapies for both dogs and people, she said.
For more information about TGen’s Valley Fever PAWS (Prevention, Awareness, Working for Solutions), visit us on Facebook at www.facebook.com/vfpaws, and on Twitter at @ValleyFeverPAWS.
Good Dog: Behavior & Training
These dogs don’t act quite like other dogs
When people accumulate animals in large enough numbers that the basic needs of those animals cannot be met, it’s called hoarding. Rescues of dogs from hoarding situations often make the news because the conditions are generally horrific—unimaginably unhealthy and unsanitary. There is usually significant malnutrition and disease, and death is common. Whenever possible, dogs rescued from such situations are nursed back to health and adopted into pet homes.
Their physical health can recover to varying degrees depending on the dog, but what about their behavioral health? There are many anecdotal reports of abnormal behavior in dogs who have been removed from hoarding situations, but the question of how hoarding affects dogs behaviorally has not been well documented. A recent study called “Behavioural characteristics of dogs removed from hoarding situations” addresses this issue by investigating how previously hoarded dogs who have been rehomed differed behaviorally and psychologically from a comparison group of rehomed pet dogs.
Dogs for the study were recruited with notices in newsletters of various rescue and shelter organizations seeking qualified dogs. To be included in the study, a dog had to have been removed from a hoarding situation. The authors of the study defined a hoarding situation as “a living environment where a person or persons accumulate animals in numbers that exceed the person’s abilities to provide for the basic needs of the animals, resulting in animal suffering”. The study included 408 dogs who had been rescued from hoarding situations.
The guardians of the hoarded dogs filled out the highly detailed Canine Behavioral Assessment and Research Questionnaire (C-BARQ), which was developed to measure various behavioral characteristics of dogs. The C-BARQ is a standard research tool used to compare the behavior of different groups of dogs.
The control group of 11,277 dogs came from the C-BARQ database and consisted of dogs of similar age and breed. All of the control dogs lived in homes with people who were not first time guardians. This was done to match the study group; fewer than 10 of the hoarded dogs were with first time guardians, a factor which has been shown to influence behavior.
Not surprisingly, many behavioral differences existed between the two groups. Dogs from hoarding situations were more fearful and more sensitive to touch than the control dogs. They showed more behavior associated with attachment, attention-seeking and separation anxiety. They exhibited a greater frequency of urination and defecation when left alone, destructive chewing, submissive urination and repetitive behaviors.
Dogs rescued from hoarding situations were less trainable and less aggressive. They were less likely than the control dogs to be overly excitable or energetic. They had a lower probability of being persistent barkers, of chasing small animals, or of exhibiting rivalry for resources with other dogs. They were not as likely to roll in foul-smelling material or to chase their own tails compared with dogs in the control group.
To sum up, there were substantial behavioral differences between dogs who had been rescued from hoarding situations and dogs with more typical life experiences. It’s easy to be dismayed when reading about the behavioral abnormalities of dogs who come from hoarding situations.
There’s good news, though, and I always like to look for the bright side. Many of these dogs can be placed in loving pet homes. Also, the more we learn about their atypical behavior, the better equipped we are to help them recover and the more motivated we are as a society to prevent such damaging situations in the first place.
Please share your experiences if you have adopted a dog who previously lived in a hoarding situation.
Good Dog: Behavior & Training
Detection dog essential for research success
For three years, scientist Chris Bugbee of Conservation CATalyst has been studying a jaguar named El Jefe, first with support from the University of Arizona and now from the Center for Biological Diversity. El Jefe is about seven years old and the only wild jaguar known to be in the United States. Most members of this species live further south, in Mexico and in other Latin American countries, but El Jefe has spent at least three years in the Santa Rita Mountains in southern Arizona. Jaguars are notoriously elusive, rarely seen and can have territories that cover hundreds of square miles, so the study of El Jefe represents a major success story. He’s not, however, the only animal associated with this study who is a success story.
The other one is a female Belgian Malinois named Mayke, who is a working detection dog. She has been trained to bark when she finds jaguar scat, which she can distinguish from the scat of other large cats. (Mayke is also trained to bark when she finds the scat of ocelot, another species of wild cat.)
Mayke was born to do scent work, coming from a program in Germany that has successfully bred many dogs for this purpose. Like her close relatives from the same lines, she has a great nose, can handle heat and is both trainable and intelligent. Even with that background, her first assignment was not a good match. She was originally placed as an explosives detection dog, but she couldn’t handle working around big trucks or gunfire. Those stresses upset her to the point that she was unable to perform the work she was trained to do, but she excels in the wide open, remote spaces where El Jefe lives, and where both dog and jaguar have been videotaped.
Detection dogs can be trained to find a huge range of things from explosives to drugs to people to invasive snails, so why was Mayke trained to find jaguar scat? The answer to that requires an understanding of how scientists view the excrement of their study animals. As a friend of mine who studied patas monkeys in Africa once said, “Most people think of poop as just poop. I think of poop as information.” (FYI, I paraphrased in order to maintain our PG rating.)
Scat is a major resource for people studying wild mammals, but it’s hard for people to find, especially when the animal in question is a jaguar and can travel 30 miles a day. Luckily, dogs are not held back, as people are, by pathetic noses and tiny olfactory lobes. A trained dog can sniff out scat, and therefore allow humans to learn so much more about an animal than would be possible on our own.
Thanks to Mayke and her trainer, biologist Chris Bugbee, it has been possible to map out El Jefe’s home range, learn what he’s eating, figure out a number of places where he likes to bed down during the day, and study his DNA. Mayke found the first genetically verified jaguar scat in the US, which is a big deal because the jaguar has not always been in this part of its historical range. It’s because of Mayke’s work that scientists have been able to place camera traps in places that El Jefe is likely to visit. The jaguar has been photographed and videotaped over a hundred times in the last three years. The understanding of El Jefe’s location and behavior, made possible by Mayke’s unique contribution to the project, have shown that El Jefe is a resident male who lives in Arizona.
According to Randy Serraglio, a conservation advocate with the Center For Biological Diversity who has studied jaguars for years, this is important because people and organizations who are reluctant to use any resources to protect him tend to refer to him as a “solitary wandering male”. That implies that he is just a vagrant temporarily lost and visiting the US. This is a nonsensical classification because males of this species are always solitary except briefly during mating. Females are also solitary except during mating and during the short period they have young with them.
Jaguars are native to Arizona. Both males and females were living and breeding in the area until people shot and poisoned them out, beginning in the early 1900s. The interest in El Jefe is helping to protect 764,000 acres of critical habitat in southern Arizona, and making it more likely that recovery efforts can re-establish a jaguar population in the area. The area is at risk of great damage to wildlife, water and the attractive landscape because of a proposed copper mine. There are many reasons to reject this environmentally damaging project, and El Jefe’s large territory is one of them.
With such a rare species, it’s important to keep as many potential breeding animals in the population as possible to maintain the genetic diversity. Previously, a male named Macho B who spent time in Arizona and was photographed there, returned to Mexico to breed, and it is likely that El Jefe is also a part of that same population.
Arizonans are quite attached to him already. That is especially true of the kids who named him. Children at Valencia Middle School in the Tucson area, whose mascot is the jaguar, picked his name. El Jefe (Spanish for “The Boss”) was the overwhelming choice in the vote among the five names that were finalists.
Perhaps the most important part of Mayke’s contribution to the study of El Jefe is that she enables scientists to learn about this jaguar in a non-invasive way. They are able to get an amazing amount of valuable data without bothering the cat. This matters for any species, but it’s especially critical when working with rare animals. Sadly, there are cases of jaguars being injured or killed because of attempts to radio collar the animal (to monitor the animal’s position) and a bad reaction to the tranquilizer. Mayke can locate signs of the animal’s presence and allow scientists to collect data without any such invasive techniques, which eliminates the risk associated with other methods of study.
When I asked Bugbee if there was anything else he wanted to share with me about Mayke, he answered, “Just that she’s a success story—even if you ignore that she’s found the first genetically verified jaguar scat in the US—because she found her confidence and came into her own.” They’ve been working together for three years and have a close relationship. Bugbee knows her well and understands her behavior. He knows the different ways that she reacts to various wild animals. If she finds scat from a puma, she pees on it. If she detects fresh deer scent from the glands in their feet, she points—holding one paw up and leaning in the direction of the deer. She also has her own unique responses to bobcats and bears.
Bugbee talks about her with great affection and respect, sounding like both the professional trainer he is and a loving dog guardian like any other, saying, “I wish I knew all of the things she picks up on. It would be incredible,” and “She’s a good dog. I like her.”
Good Dog: Behavior & Training
Experience with relevant objects has no effect
Anyone whose dog loves to get into the garbage for a trash party or is better than Houdini at escaping from a crate knows that dogs are problem solvers. In fact, their ability to solve problems is an active area of research, and the results are not always intuitively obvious. (That’s the way that scientists express what other people might say as, “Whoa! That’s not what I expected!”)
In the study, “Inhibitory Control, but Not Prolonged Object-Related Experience Appears to Affect Physical Problem-Solving Performance of Pet Dogs”, researchers studied how two factors relate to how well dogs solve problems presented as physical tasks. Specifically, they wanted to know whether the ability to inhibit themselves was correlated with increased problem solving ability and whether experience with objects relevant to the problems made a difference. These two variables were chosen for investigation because there is evidence that they are both important in problem solving ability across a range of species, including humans.
In order to address these questions, they recruited 63 Border Collie puppies in pet homes and studied them over a period of three years. Each dog was randomly assigned to one of three groups that differed in their experiences with physical tasks.
The first group (enrichment group) received toys that gave them the opportunity to learn about the physical effects of gravity, attachment, and support and also a set of toys that required attending to a size differential between objects to access a treat. The second group (manipulative group) received toys that gave them the same opportunity as the first group to manipulate toys, to push and pull on handles and other parts of the toys, but which did not teach them about the effects of such actions or the importance of relative size. The third group (control group) had only the typical toys used by guardians for stimulation, such as ropes, balls and various rubber toys. The dogs in the experimental and manipulative groups (but not in the control group) took part in a string-pulling study that provided an additional educational experience about the physical effects of their actions.
All dogs, no matter which experience group they were in, were taught three inhibitory tasks. One was being required to wait for permission before taking a treat on the floor in front of them. (This task is often called “Leave It” though some people using this cue never allow the dog to take the treat he was told to leave.)
The second involved the opportunity to obtain a treat from underneath each of two transparent cups turned upside down. The catch was that there were three cups and the dog would only be permitted to knock over two of them. He had to avoid knocking over the empty cup, as the final cup was made unavailable after the dog had knocked over two cups. This is very hard for dogs, especially if the empty cup is in the middle between the cups with treats.
The third task involved the dog being caught by his leash on something like a tree or a lamp post. The guardian would call the dog, but the dog had to first move away from the person in order to untangle himself.
To assess dogs’ level of inhibitory control, they were tested on each of the tasks after a month of practice and scored on a scale of 0 to 2, which 2 representing the highest level of inhibition. This study did not distinguish between learned and inherent levels of inhibition, but simply looked a dog’s ability when tested to control himself in the various tasks.
To sum up, dogs were given one of three levels of experience with objects and their levels of inhibitory control were assessed. They were then tested with four problem-solving tasks. The problems were all designed to be difficult in order to detect potential improvement based on experience. (If the tasks were too easy, researchers would be unlikely to detect any role of experience in dogs’ ability to solve the problem.)
One main result of the study is that there was no difference found in the problem-solving abilities between the three groups of dogs. That is, success at solving the problems was not related to whether a dog was in the enriched, manipulation or control group. Another result of the study was that dogs’ inhibition scores were related to their performance in two of the problem-solving tasks, but not the other two. Of the two tasks in which performance was related to inhibition, one task was positively associated with success (high inhibition predicted success at solving the problem) and the other was negatively associated with success (a low level of inhibition predicted success at performing the task correctly).
The dogs in this study did not exhibit the ability to transfer knowledge about physical rules learned in one situation to another, similar situation. The researchers conclude that dogs do not generalize from one problem-solving task to another. They hypothesize that dogs approach each problem as a novel task unrelated to others that they have already solved.
I’m curious about these conclusions because of my own experiences observing dogs. I don’t have data on canine problem solving, so my surprise about this study’s results only reflects my anecdotal observations. It seems that dogs who understand how to get food from one style of Kong or toy have an easier time figuring out similar puzzles. It also seems that once a dog has solved the mystery of one “secure” trash can, others are quick to be defeated by that same dog. Perhaps experience only matters with highly similar tasks, or when the task is presented in the same location. Another possibility is that if the motivation to solve the problem is high enough, a dog will perform at a higher level. Kongs and trash cans may provide more motivation than a puzzle in a lab setting. All of these variables would be interesting to explore in future studies. Such work is incredibly intensive and time-consuming, and I applaud these researchers for investigating canine problem solving abilities in a long-term, controlled experiment.
Do the conclusions of this study match your expectations?
Culture: Science & History
How Humans and Their Dogs Drove Neanderthals to Extinction
Pat Shipman, PhD, is a retired adjunct professor of anthropology at Penn State and an internationally recognized expert in taphonomy, the study of how living animals are transformed into skeletons, and then fossils. Her scientific training and boundless curiosity lead her to take on the intriguing question of just why Homo neaderthalensis, one of the most successful apex species of hunters who had thrived for millennium in Eurasia, would almost suddenly, anthropologically speaking, become extinct. Her hypothesis: The Invaders: How Humans and Their Dogs Drove Neanderthals to Extinction (The Belknap Press) points to the abilities of both certain wolves and our ancestors to pair up and this gave them the competitive edge in the battle of survival. It is certainly true that this wasn’t done intentionally, but such an evolutionary breakthrough resulted in an alliance that had devastating effects on not just the Neanderthals but on a long species list including the huge woolly mammoth, saber-toothed tigers and Cave bears. Could it be possible “man’s best friend” have been the Neanderthals’ worst nightmare ? Shipman’s thesis starts with Homo sapiens, who in expanding north out of Africa were not only as an invasive species, but the most invasive in history, wreaking ecologically enormous changes throughout continents. The evidence that she relies on, by a meticulous review of the most current archeological research and genomic and genetic studies, can perhaps most readily be seen in the mammoth remains megasites, where the number of kills increases almost exponentially after the first evidence of the wolf-dog–human alliance was discovered. For ten thousand years before the domestication of the wolf-dog, evidence of early humans hunting mega-fauna like mammoth is scant, but with the addition of the superior hunting and tracking talents that wolf-dogs contributed to our projectile throwing ancestors lead not only to more successful kills of large prey but insured the success of our two predatory species. As for the Neanderthal, it wasn’t just simply that humans bested them as hunters but climate change was also a key contributing factor: but the combo of the alliance of the apex predators with the ice age ensured their extinction, so goes evolution. As Shipman notes about the Jagger Principle, “… the immortal words of Mick Jagger (yes that one) and Keith Richards are the best statement I know of to describe evolution. Things don’t stay the same; you can’t always get what you want; but with a little flexibility, you might get what you need to survive.” This is truly a fascinating and thought-provoking book, and Shipman presents a compelling argument for how canines and humans proved their flexibility and how this could have been the main reason that we survived and the Neanderthals didn’t. But drawing upon the wisdom of another ’60s duo, we also got by with a little help from our [first] friends. See the following interview with Dr. Shipman to learn more.
Bark: How long did it take humans, once they migrated out of Africa, to team up with wolves, a species that was unknown in Africa?
Pat Shipman: There were wolves in North Africa, but my guess is that humans did not team up with them but rather, based on genetic information, with European wolves. The earliest humans in Europe date to perhaps 42,000 years ago. The earliest wolf-dogs we know at present show up about 34,000 years ago (or about 37,000, if the raw radiocarbon date is calibrated for irregularity in the deterioration of C-14). Thus, it may have taken 6,000 years, or less—I seriously doubt we have found the first wolf anyone ever attempted to domesticate.
BK: What environmental reasons led to this amazing partnership?
PS: There were many different predators in Europe when modern humans arrived; competition for prey was considerable, and even worse once humans came on the scene. The idea of domesticating any animal was completely unknown, but somehow— probably by accident—some wolves began cooperating with some humans because the alliance benefited both.
They caught more prey, faster, with less risk to canine or human, which meant more energy for reproduction. Wolves had a set of skills for hunting in packs: speed, keen ears, a very keen sense of smell, sharp teeth and claws. Early humans were much slower, had lousy senses of smell and hearing, and blunt teeth, but they had distance weapons that could kill an animal while avoiding injury from close contact. By teaming up with special wolves—wolfdogs they could capture a much wider array of animals with much less risk and less expenditure of energy. They were nearly unstoppable.
BK: You write that proto-dogs were like “living tools” to humans. Was this a mutually beneficial arrangement?
PS: Absolutely. You cannot force any animal to cooperate if it does not want to. You cannot force an animal not to be hostile to humans or to cooperate with humans if there is no benefit to the animal.
BK: Wolves are highly territorial, and may kill other wolves who come into their area. Since this was well before human settlements, humans and wolf-dogs would have traveled great distances, through other species’ (i.e., wolves’) territory. Could the advantage to the wolfdogs come from the protection offered by their human partners?
PS: Both wolf-dogs and humans were more efficient hunters through cooperation— the wolf-dogs by having hunters kill the prey from a distance after they had found it, isolated it and stressed it through charging and holding it at bay.
For wolf-dogs and humans to travel together, they must have cooperated to drive off or kill the wolf packs through whose territories they passed. Indeed, there is a marked rise in the number of wolf bones in human sites after wolf-dogs appear. I think wolves were deliberately targeted by humans in order to protect the wolf-dogs, and to protect the remains of their kills from scavengers.
BK: Why do you think that Neanderthals did not also have wolf-dogs?
PS: One quite real possibility is that modern humans had adaptations that fostered better communication with wolf-dogs and possibly (we don’t know) Neanderthals did not. For example, humans are the only primates with whites to their eyes, which makes communicating the “direction of gaze”— where you are looking—very obvious. This is a huge advantage in silent cooperative hunting. We do not yet know if Neanderthals had this adaptation or not. Assuming that they saw humans working with wolf-dogs, why Neanderthals did not steal them or make their own is unclear. Humans undoubtedly prized the canines and may have gone to great lengths to prevent them from being stolen. Maybe Neanderthals did not have the empathy and ability to understand wolf-dogs that is so necessary to a good working relationship. Maybe Neanderthals tried and just couldn’t figure out how to handle them.
BK: What do you think inspired humans to see that teaming up with wolves might give them a competitive edge? Did it have to do with their diet perhaps?
PS: I don’t think humans set out to domesticate wolves into dogs; I think it was an accident based on taking in orphaned puppies and raising them. Before working with wolf-dogs, humans were rarely able to kill mammoths or other very large game; afterward, there are sites with dozens of mammoth kills. I suspect that killing mammoths efficiently and regularly required the help of wolf-dogs, so mammoths weren’t really a preferred human food until humans had wolfdogs to help.
BK: It was interesting that the primary protein source in the bones of both wolfdogs and humans can be detected. What does that tell us?
PS: First, this sort of study tells us that, at the same site, wolf-dogs and wolves ate different prey animals predominantly. (That is a very surprising finding if my colleagues and I are mistaken and the wolf-dogs are really wolves, that would make them a very odd and distinctive group.) Second, this type of study shows us that humans may have provisioned wolf-dogs, rather than letting them simply eat whatever was left over.
BK: You say that wolf-dogs were a first, but unsuccessful, attempt at domestication; and that domestication happened several times in different areas. Are you concerned that their mtDNA (mitochondrial DNA) evidence hasn’t been found in modern-day canids?
PS: Not at all. There is as much mtDNA evidence that these identified wolf-dogs were wolves as there is that they were dogs: none. The mtDNA we have so far from wolf-dogs is unique, previously unknown. What that means is uncertain.
This particular genetic material is passed from mother to daughter to granddaughter and so on; the father’s mtDNA is not. This means that if you have a small population with an unusual mtDNA, the probability that it will go extinct in 1,000 years—much less 35,000—is very, very, very high.
It could be as simple as a few females who don’t reproduce successfully or have only males due to random chance. Also, athough we have several thousand mtDNA lineages from living animals, there are millions of dogs and wolves whose mtDNA is unknown. Maybe the sample sizes of living animals are too small and the wolf-dog mtDNA is still out there somewhere. Maybe it is simply extinct.
The standard calculation is that 99 percent of all mtDNA lineages go extinct, so we can’t conclude too much from that. I am not at all worried that the mtDNA information from wolfdogs has not yet been matched in any other group. Also, the entire wolf-dog group may well have gone extinct, with a still-later domestication of wolves into dogs. We just don’t know.
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