Tag Archives: wolves

Researchers identify a common underlying genetic basis for social behavior in dogs and humans

Dogs’ ability to communicate and interact with humans is one the most astonishing differences between them and their wild cousins, wolves. A new study published in the journal Science Advances identifies genetic changes that are linked to dogs’ human-directed social behaviors and suggests there is a common underlying genetic basis for hyper-social behavior in both dogs and humans.

An interdisciplinary team of researchers, including those from Princeton University, sequenced a region of chromosome 6 in dogs and found multiple sections of canine DNA that were associated with differences in social behavior. In many cases, unique genetic insertions called transposons on the Williams-Beuren syndrome critical region (WBSCR) were strongly associated with the tendency to seek out humans for physical contact, assistance and information.

In contrast, in humans, it is the deletion of genes from the counterpart of this region on the human genome, rather than insertions, that causes Williams-Beuren syndrome, a congenital disorder characterized by hyper-social traits such as exceptional gregariousness.

“It was the remarkable similarity between the behavioral presentation of Williams-Beuren syndrome and the friendliness of domesticated dogs that suggested to us that there may be similarities in the genetic architecture of the two phenotypes,” said Bridgett vonHoldt, an assistant professor in ecology and evolutionary biology at Princeton and the study’s lead co-author.

Dogs ability to communicate

Dogs’ ability to communicate and interact with humans is one of the most astonishing differences between them and their wild cousins, wolves. Shown here, Lauren Brubaker, a graduate research assistant in the Department of Animal and Rangeland Sciences at Oregon State University and one of the study’s authors, interacts with a gray wolf. Photo by Monty Sloan

VonHoldt had identified the canine analog of the WBSCR in her publication in Nature in 2010. But it was Emily Shuldiner, a 2016 Princeton alumna and the study’s other lead co-author, who, as part of her senior thesis, pinpointed the commonalities in the genetic architecture of Williams-Beuren syndrome and canine tameness.

By analyzing behavioral and genetic data from dogs and gray wolves, vonHoldt, Shuldiner and their colleagues reported a strong genetic aspect to human-directed social behavior by dogs. Monique Udell, an assistant professor of animal and rangeland sciences at Oregon State University and the paper’s senior author, collected and analyzed the behavioral data for 18 domesticated dogs and 10 captive human-socialized wolves, as well as the biological samples used to sequence their genomes.

First, Udell quantified human-directed sociability traits in canines, such as to what extent they turned to a human in the room to seek assistance in trying to lift a puzzle box lid in order to get a sausage treat below or the degree to which they sought out social interactions with familiar and unfamiliar humans. Then, vonHoldt and Shuldiner sequenced the genome in vonHoldt’s lab and correlated their findings.

Consistent with their hypothesis, the researchers confirmed that the domesticated dogs displayed more human-directed behavior and spent more time in proximity to humans than the wolves. The also discovered that some of these transposons on the WBSCR were only found in domestic dogs, and not in wolves at all.

VonHoldt’s findings suggest that only a few transposons on this region likely govern a complex set of social behaviors. “We haven’t found a ‘social gene,’ but rather an important [genetic] component that shapes animal personality and assisted the process of domesticating a wild wolf into a tame dog,” she said.

Anna Kukekova, an assistant professor in the Department of Animal Sciences at the University of Illinois at Urbana-Champaign who is familiar with the research but had no role in it, said that the paper points to these genes as being evolutionarily conserved, or essentially unchanged throughout evolution. “The research provides evidence that there exist certain evolutionary conservative mechanisms that contribute to sociability across species,” she said. “That they have found that this region contributes to sociability in dogs is exciting.”

The researchers’ evidence also calls into question the role of domestication in the evolution of canine behavior. Most experts agree that the first domesticated dogs were wolves that ventured into early human settlements. These proto-dogs evolved not only in their looks, but also their behavior, a process likely influenced by the species’ cohabitation, according to vonHoldt.

However, unlike previous research which suggests that, during the process of domestication, dogs were selected for a set of cognitive abilities, particularly an ability to discern gesture and voice, vonHoldt and Shuldiner’s research posits that dogs were instead selected for their tendency to seek human companionship.

“If early humans came into contact with a wolf that had a personality of being interested in them, and only lived with and bred those ‘primitive dogs,’ they would have exaggerated the trait of being social,” vonHoldt said.

Source:  Princeton University media statement

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Gambling wolves take more risks than dogs

Would you rather get 100 euros for certain, or have a fifty-fifty chance of receiving either 200 euros or nothing? Most choose the first, as humans tend to be “risk-averse”, preferring a guaranteed pay-off over the possibility of a greater reward. It is thought that the human preference for “playing it safe” has evolved through natural selection: when you live precariously, like our remote ancestors, losing all your food reserves might be catastrophic, while adding to them might not make much difference to your chances of survival.

Wolf pups

Etu and Ela, two wolf pups at the Wolf Centre Photo credit: Rooobert Bayer

Here, in one of the first studies on risk preferences in animals other than primates, scientists show that wolves are consistently more prone to take risks when gambling for food than dogs. When faced with the choice between an insipid food pellet and a fifty-fifty chance of either tasty meat or an inedible stone, wolves nearly always choose the risky option, whereas dogs are more cautious.

“We compared the propensity to take risks in a foraging context between wolves and dogs that had been raised under the same conditions,” says Sarah Marshall-Pescini, a postdoctoral fellow at the Messerli Research Institute at the Veterinary University of Vienna and the Wolf Science Centre, Ernstbrunn, Austria, the study’s first author. “We found that wolves prefer the risky option significantly more often than dogs. This difference, which seems to be innate, is consistent with the hypothesis that risk preference evolves as a function of ecology.”

The study was done at the Wolf Science Centre, Ernstbrunn, Austria, a research institute where scientists study cognitive and behavioral differences and similarities between wolves and dogs. Here, wolves and dogs live in packs, under near-natural conditions within large enclosures.

Marshall-Pescini let each of 7 wolves and 7 dogs choose 80 times between two upside-down bowls, placed side-by-side on a movable table-top. The animals had been trained to indicate the bowl of their choice with their paw or muzzle, after which they would receive the item that was hidden beneath it.

The researchers had taught the wolves and dogs that beneath the first bowl, the “safe” option, was invariably an insipid food pellet, while beneath the second bowl, the “risky” option, was either an inedible item, a stone, in a random 50% of trials, and high-quality food, such as meat, sausage, or chicken, in the other 50%. As a control, the side for the “safe” and “risky” option changed between trials, but the animals were always shown which side corresponded to which option; whether they would get a stone or high-quality food if they chose the “risky” option was the only unknown. Rigorously designed control trials confirmed that the animals understood this rule, including the element of chance.

Wolves are much more prone to take risks than dogs, show the results. Wolves chose the risky option in 80% of trials, whereas dogs only did so in 58% of trials.

The researchers believe that dogs evolved a more cautious temperament after they underwent an evolutionary shift from their ancestral hunter lifestyle to their present scavenger lifestyle, which happened between 18,000 to 32,000 years ago when humans first domesticated dogs from wolves. Previous research has suggested that species that rely on patchily distributed, uncertain food sources are generally more risk-prone. For example, chimpanzees, which feed on fruit trees and hunt for monkeys, are more risk-prone than bonobos, which rely more on terrestrial vegetation, a temporally and spatially reliable food source.

“Wild wolves hunt large ungulates — a risky strategy, not only because hunts often fail, but also because these prey animals can be dangerous — whereas free-ranging dogs, which make up 80% of the world’s dog population, feed mostly by scavenging on human refuse, a ubiquitous, unlimited resource. So dogs no longer need to take risks when searching for food, and this may have selected for a preference to play if safe,” concludes Marshall-Pescini.

Source:  EurekAlert! media statement

New twist in tale of dogs’ origins

The origin of dogs has inspired a lingering controversy in academia. Where and when did dogs first split off from wolves? One of the top dogs in this dispute, population genetics expert Peter Savolainen of Sweden’s KTH Royal Institute of Technology, isn’t about to roll over. He hopes his latest research will finally settle the matter.

Some researchers say canines first split off from wolves in the Middle East; others say it happened in Europe. But Savolainen has long held that dogs originated in South East Asia alone, and he says his team has compiled new evidence that confirms his earlier findings.

The study concludes that the split with wolves occurred about 33,000 years ago.

Savolainen’s earlier studies were based on analysis of mitochondrial DNA. But recently other researchers have used data from nuclear DNA to refute those findings, arguing that dogs originated in the Middle East, Central Asia or Europe.

But apparently, those researchers were thrown off the scent, according to Savolainen. The data they relied on did not include samples from South East Asia, he says. So if, as Savolainen says, dogs did indeed come from South East Asia, these studies would not have been able to detect it.

Photo by IStock

Photo by IStock

“Which is why we analysed the entire nuclear genome of a global sample collection from 46 dogs, which includes samples from southern China and South East Asia,” he says. “We then found out that dogs from South East Asia stand out from all other dog populations, because they have the highest genetic diversity and are genetically closest to the wolf.”

Savolainen says this provides strong evidence that the dog originated in South East Asia, which confirms his earlier studies of Mitochondrial DNA.

“We also found that the global dog population is based on two important events: the dog and wolf populations first began to split off about 33,000 years ago in South East Asia. The global spread of dogs followed about 18,000 years later.

He says one explanation for the split between dogs and wolves 33,000 years ago could be that the wolf population became divided and the south Chinese wolf developed into dogs. In that case, it is possible the global spread of dogs out of South East Asia is associated with domestication.

“The dog’s story thus appears to have begun 33,000 years ago, but the exact path to the fully-domesticated dogs that spread throughout the world 15,000 years ago is not yet clear,”

Savolainen, along with 14 other scientists, recently published the scientific article “Out of Southern East Asia: The Natural History of domestic dogs across the world.

Source:  AlphaGalileo media release

A bond that goes way back

The special relationship between humans and dogs may go back 27,000 to 40,000 years, according to genomic analysis of an ancient Taimyr wolf bone reported in the Cell Press journal Current Biology on May 21. Earlier genome-based estimates have suggested that the ancestors of modern-day dogs diverged from wolves no more than 16,000 years ago, after the last Ice Age.

The genome from this ancient specimen, which has been radiocarbon dated to 35,000 years ago, reveals that the Taimyr wolf represents the most recent common ancestor of modern wolves and dogs.

his image compares an ancient Taimyr Wolf bone from the lower jaw to a modern pipette.  Photo by Love Dalén

This image compares an ancient Taimyr Wolf bone from the lower jaw to a modern pipette. Photo by Love Dalén

“Dogs may have been domesticated much earlier than is generally believed,” says Love Dalén of the Swedish Museum of Natural History. “The only other explanation is that there was a major divergence between two wolf populations at that time, and one of these populations subsequently gave rise to all modern wolves.” Dalén considers this second explanation less likely, since it would require that the second wolf population subsequently became extinct in the wild.

“It is [still] possible that a population of wolves remained relatively untamed but tracked human groups to a large degree, for a long time,” adds first author of the study Pontus Skoglund of Harvard Medical School and the Broad Institute.

The researchers made these discoveries based on a small piece of bone picked up during an expedition to the Taimyr Peninsula in Siberia. Initially, they didn’t realize the bone fragment came from a wolf at all; this was only determined using a genetic test back in the laboratory. But wolves are common on the Taimyr Peninsula, and the bone could have easily belonged to a modern-day wolf. On a hunch, the researchers decided to radiocarbon date the bone anyway. It was only then that they realized what they had: a 35,000-year-old bone from an ancient Taimyr wolf.

The DNA evidence also shows that modern-day Siberian Huskies and Greenland sled dogs share an unusually large number of genes with the ancient Taimyr wolf.

“The power of DNA can provide direct evidence that a Siberian Husky you see walking down the street shares ancestry with a wolf that roamed Northern Siberia 35,000 years ago,” Skoglund says. To put that in perspective, “this wolf lived just a few thousand years after Neandertals disappeared from Europe and modern humans started populating Europe and Asia.”

Source:  EurekAlert! media statement

Dog-human cooperation is based on social skills of wolves

Dogs are man’s best friend and partner. The origins of this dog-human relationship were subject of a study, published recently in the journal Frontiers in Psychology,  by behavioural scientists from the Messerli Research Institute at the Vetmeduni Vienna and the Wolf Science Center.

They showed that the ancestors of dogs, the wolves, are at least as attentive to members of their species and to humans as dogs are. This social skill did not emerge during domestication, as has been suggested previously, but was already present in wolves. 

Photo by the Wolf Science Center

Photo by the Wolf Science Center

Commonly accepted hypotheses about domestication suggest: “Dogs have become tolerant and attentive as a result of humans actively selecting for these skills during the domestication process in order to make dogs cooperative partners.”

Friederike Range and Zsófia Virányi from the Unit of Comparative Cognition at the Messerli Research Institute question the validity of this view and have developed the “Canine Cooperation Hypothesis”. Their hypothesis states that since wolves already are tolerant, attentive and cooperative, the relationship of wolves to their pack mates could have provided the basis for today’s human-dog relationship. An additional selection, at least for social attentiveness and tolerance, was not necessary during canine domestication.

The researchers believe that wolves are not less socially attentive than dogs. Dogs however cooperate more easily with humans because they more readily accept people as social partners and more easily lose their fear of humans. To test their hypothesis, Range and Virányi examined the social attentiveness and tolerance of wolves and dogs within their packs and toward humans.

Various behavioural tests showed that wolves and dogs have quite similar social skills. Among other things, the researchers tested how well wolves and dogs can find food that has been hidden. Both wolves and dogs used information provided by a human to find the hidden food.

In another study, they showed that wolves followed the gaze of humans. To solve the task, the animals may need to be capable of making a mental representation of the “looker’s” perspective. Wolves can do this quite well. 

Another experiment gave dogs and wolves the chance to observe conspecifics as they opened a box. When it was the observer’s turn to do the same, the wolves proved to be the better imitators, successfully opening the box more often than dogs. “Overall, the tests showed that wolves are very attentive to humans and to each other. Hypotheses which claim that wolves have limited social skills in this respect in comparison to dogs are therefore incorrect,” Range points out. 

At the Wolf Science Center in Ernstbrunn in Lower Austria, Range and Virányi investigated the social behaviour of dogs and wolves that grew up with members of their species and with humans. “The animals are socialized both with conspecifics and with humans. To be able to compare the behaviour of dogs and wolves and to investigate the effects of domestication, it is important that the animals live in the same conditions,” Virányi explains.

Source:  Vetmeduni Vienna media release

Read my other post about the Institute’s research with wolves here

Kathleen Crisley, specialist in dog massage, rehabilitation and nutrition/food therapy, Canine Catering Ltd, Christchurch, New Zealand

Teaching wolves new tricks

The process of learning often involves mimicry or imitation.  In research published in the journal PLoS One, scientists from the Messerli Research Institute at the University of Veterinary Medicine, Vienna report on their behaviour experiments involving wolves and dogs.

The results show that wolves observe one another more closely than dogs and so are better at learning from one another. 

Photo Credit: Walter Vorbeck

Photo Credit: Walter Vorbeck

The scientists found that wolves are considerably better than dogs at opening a container, providing they have previously watched another animal do so. Their study involved 14 wolves and 15 mongrel dogs, all about six months old, hand-reared and kept in packs.

Each animal was allowed to observe one of two situations in which a trained dog opened a wooden box, either with its mouth or with its paw, to gain access to a food reward. Surprisingly, all of the wolves managed to open the box after watching a dog solve the puzzle, while only four of the dogs managed to do so. Wolves more frequently opened the box using the method they had observed, whereas the dogs appeared to choose randomly whether to use their mouth or their paw.

The researchers think that it is likely that the dog-human cooperation originated from cooperation between wolves. During the process of domestication, dogs have become able to accept humans as social partners and thus have adapted their social skills to include interactions with them, concomitantly losing the ability to learn by watching other dogs.

Source:  University of Vienna media release

The ability for dogs and wolves to learn

Wolves can learn from observing humans and pack members where food is hidden and recognize when humans only pretend to hide food, reports a study published for the first time in the open-access journal Frontiers in Psychology.

The researchers conclude that the ability to learn from other species, including humans, is not unique to dogs but was already present in their wolf ancestors. Prehistoric humans and the ancestors of dogs could build on this ability to better coordinate their actions.  Photo by Wolf Science Center

The researchers conclude that the ability to learn from other species, including humans, is not unique to dogs but was already present in their wolf ancestors. Prehistoric humans and the ancestors of dogs could build on this ability to better coordinate their actions. Photo by Wolf Science Center

These findings imply that when our ancestors started to domesticate dogs, they could have built on a pre-existing ability of wolves to learn from others, not necessarily pack members.

A paper published recently in the journal Science suggested that humans domesticated dogs about 18 thousand years ago, possibly from a European population of grey wolves that is now extinct. But it remains unknown how much the ability of dogs to communicate with people derives from pre-existing social skills of their wolf ancestors, rather than from novel traits that arose during domestication.

In a recent study, Friederike Range and Zsófia Virányi from the Messerli Research Institute at the University of Veterinary Medicine Vienna investigated if wolves and dogs can observe a familiar “demonstrator” – a human or a specially trained dog – to learn where to look for food within a meadow. The subjects were 11 North American grey wolves and 14 mutts, all between 5 and 7 months old, born in captivity, bottle-fed, and hand-raised in packs at the Wolf Science Center of Game Park Ernstbrunn, Austria.

The wolves and dogs were two to four times more likely to find the snack after watching a human or dog demonstrator hide it, and this implies that they had learnt from the demonstration instead of only relying on their sense of smell. Moreover, they rarely looked for the food when the human demonstrator had only pretended to hide it, and this proves that they had watched very carefully.

The wolves were less likely to follow dog demonstrators to hidden food. This does not necessarily mean that they were not paying attention to dog demonstrators: on the contrary, the wolves may have been perceptive enough to notice that the demonstrator dogs did not find the food reward particularly tasty themselves, and so simply did not bother to look for it.

Source:  EurekAlert! press release