WOLVES AND DOGS

WOLVES AND DOGS

20120207-Shar_Pei_1.jpg
Shar Pei, one of the
oldest dog breeds
All dogs (Canis lupus familiaris) descended from the gray wolf, the largest member of the Canidae family. Dogs and wolves are still capable of interbreeding. Wolf-dog crossbreeds are very unpredictable and potentially dangerous. One wolf-dog crossbreed heard a couch spring squeak and then tore up upholstery searching for a mouse.

Dogs are believed to have been the first animals to be domesticated by ancient humans. Most archaeologists believe that dogs were first domesticated about 14,000 years ago. This was before the development of agriculture and permanent human settlements.There are currently about 400 million dogs in the world and 400,000 wolves. [Source: Xiaoming Wang and Richard Tedford, Natural History magazine, July-August 2008; Angus Phillips, National Geographic, January 2002]

Dogs and canids (wolf-like and dog-like animals) evolved from hesperocyons, predators that looked somewhat like jackals and lived 37 million years ago in North America. They had distinctive pairs of shearing teeth and ran down prey. Some regard the first canid as Prophesperocyon wilsoni , a creature that lived in what is now southwestern Texas about 40 million years and had teeth that were evolved towards a more shearing bite. It ancestors had more elongated limbs and toes packed close together which facilitated running faster. As their prey began runner faster they too adapted by running faster themselves They also developed the ability to crack and eat bones, which suggests that regularly scavenged carcasses.

Early canids reached Europe about 7 million years ago. The Eucyon, a species that arose 7 million years and moved west 6 million to 4 million years ago, gave birth to most modern canids, including wolves, coyotes, jackals and dogs.

Dogs have played an important role in human culture for thousands of years.The archaeological record of dogs dates back to 31,000 years ago to a Great-Dane-like species found in Belgium. There are archaeological records of dogs going back 26,000 years in the Czech Republic and 15,000 years in Siberia, said Robert Wayne, a professor of evolutionary biology at UCLA and a dog evolution expert. But canine records in the New World aren't as detailed or go back nearly as far.The first Middle East dogs appeared 12,000 to 13,000 years ago. Unlike domesticated livestock, which has been closely related to agriculture, dogs have had closer links to hunters and gatherers.

Websites and Resources on Prehistory: Human Prehistory users.hol.gr/~dilos/prehis.htm ; Wikipedia article on Prehistory Wikipedia ; Early Humans elibrary.sd71.bc.ca/subject_resources ; Prehistoric Art witcombe.sbc.edu/ARTHprehistoric ; National Geographic Atlas of the Human Journey genographic.nationalgeographic.com/genographic/atlas ; Early Modern Man: Evolution of Modern Humans anthro.palomar.edu ; Virtual Ice Age creswell-crags.org.uk/Explore/virtually-the-ice-age ; Stone Age Tools aerobiologicalengineering.com

Websites and Resources of Early Agriculture and Domesticated Animals: Origins of Agriculture comp-archaeology.org/AgricultureOrigins ; Britannica britannica.com/ ; Wikipedia article History of Agriculture said that ; History of Food and Agriculture museum.agropolis ; Wikipedia article Animal Domestication Wikipedia ; Cattle Domestication geochembio.com ; Food Timeline, History of Food foodtimeline.org ; Food and History teacheroz.com/food ;Iceman Photscan iceman.eurac.edu/ ; Otzi Official Site iceman.it

31,700-Year-Old Dog Remains Found in a Belgian Cave

It can be very difficult to distinguish between wolf and dog skeletons, especially early in the history of dogs, when they would have been much more similar to wolves than they are today. What are perhaps the earliest dog-like remains date to 31,700 years ago and were first excavated in the 19th century at Goyet Cave in Belgium. Paleontologist Mietje Germonpré of the Royal Belgian Institute of Natural Sciences recently led a team that studied a canid skull from the cave and concluded that it had a significantly shorter snout than wolves from the same period. [Source: Jarrett A. Lobell and Eric Powell, Archaeology magazine, September/October 2010]

This dog-like wolf could represent the first step toward domestication and would make the Paleolithic people we call the Aurignacians, better known as the first modern humans to occupy Europe, the world's first known dog fanciers. But the analysis is controversial, and there is a large gap between the age of the Goyet Cave "dog" and the next oldest skeletons that could plausibly be called dog-like, which date to 14,000 years ago in western Russia. Perhaps the Goyet Cave wolf represents an isolated instance of domestication and left no descendants. But based on finds of dog skeletons throughout the Old World, from China to Africa, we know that certainly by 10,000 years ago dogs were playing a critical role in the lives of humans all over the world, whether as sentries, ritual sacrifices, or sources of protein.

The oldest known evidence of what is thought to be domesticated dog according to some is a 14,000-year-old jaw bone found in a Paleolithic grave at Oberkassel in Germany. The dog was regarded as domesticated because it was valued enough to be buried. Buried dog bones from around the same time have been found in Iraq and Israel. A 12,000-year-old grave in Israel contains the remains of a human cradling the bones of wolf or dog puppy. This is some of the earliest evidence of dog domestication. Canine bones have been found at 400,000-year-old human settlements but scientists regarded these bones of tame wolves not dogs.

DNA Evidence of Dog Domestication in the Middle East

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basenji, one of
the oldest dog breeds
Genetic studies made public March 2010 indicate that dogs were domesticated in the Middle East not the Far East as had been previously suggested. In the study published online in the journal Nature by a team led by Robert Wayne, a professor of evolutionary biology at UCLA, genetic comparisons were made between 900 dogs from 85 breeds and over 20 gray wolves, the closest living wild relatives of dogs. Using molecular genetic techniques, the scientists looked at more than 48,000 markers in the entire genome---or DNA sequence---of each animal in the study.

What the scientists found was that the vast majority of dogs share unique genetic markers with gray wolves from the Middle East than other wild population, with a small number of East Asian dog breeds having similarities with wolves from China . The finding is consistent with archaeological data that links the domestication of dogs---as well as cats and many livestock animals---with the rise of human civilization in the Fertile Crescent in modern-day Iraq, Syria, Lebanon and Jordan.

the finding that all dogs evolved from wolves in East Asia came from comparison between a single, small DNA sequence taken from mitochondria. Wayner told Reuters, the new research was far more comprehensive and “is much more consistent with the archaeological record...We know that dogs from the Middle East were closely associated with humans because they were found in human burial sites.

DNA Evidence of Dog Domestication in East Asia

A DNA study conducted by Swedish team concluded that East Asia was the most likely place of origin for domesticated dogs. In the study DNA was taken from 654 dogs from around the world, and the scientists found the most genetic variation among dogs in China---which suggests that they have lived there the longest, mixing up their genes---thus concluding that dogs originated there. The evidence also suggest the transformation took place around 15,000 years ago.

A 1997 study based of an analysis of genetic material suggests that domestication may have occurred as long as 135,000 years ago. The study. done by biologists at UCLA, was based on DNA samples from coyotes, jackals, 67 breeds of dog and 27 wolf population throughout Europe, Asia and North America. The scientists found that the present-day breeds of dogs carried the genetic fingerprints of a single female similar to way humans carry the genetic material of a single female dubbed as Eve. The wide variety of genetic variation of dog species is presented as evidence that dogs were domesticated much earlier than previously thought.

DNA evidence also suggests that wolves were domesticated on four separate occasions or were domesticated once and then dogs and wolves interbred later. Dog probably mated freely with wolves for thousands of years before they were selectively bred. Scientists believe that early dogs resembled wolves and did not being looking like domestic dogs until around 10,000 to 15,000 years ago.

DNA studies have also showed that wolves are the only ancestors of dogs and that jackals and coyotes broke off from the family tree much earlier than dogs evolved from wolves. New World dogs appear to have crossed the Bering land bridge with the first human settlers more than 12,000 years ago. DNA from ancient dogs found in California and Alaska show close links to ancient dogs from Europe and Asia, suggesting that they too descended from Old World rather than New World wolves.

9,400-Year-Old Domesticated Dog, a Food Source in the Americas?

In 2011, AP reported: “Nearly 10,000 years ago, man's best friend provided protection and companionship---and an occasional meal. That's what researchers are saying after finding a bone fragment from what they are calling the earliest confirmed domesticated dog in the Americas. [Source: Clarke Canfield, Associated Press, January 19, 2011]

University of Maine graduate student Samuel Belknap III came across the fragment while analyzing a dried-out sample of human waste unearthed in southwest Texas in the 1970s. A carbon-dating test put the age of the bone at 9,400 years, and a DNA analysis confirmed it came from a dog---not a wolf, coyote or fox, Belknap said. Because it was found deep inside a pile of human excrement and was the characteristic orange-brown color that bone turns when it has passed through the digestive tract, the fragment provides the earliest direct evidence that dogs---besides being used for company, security and hunting---were eaten by humans and may even have been bred as a food source, he said.

Belknap wasn't researching dogs when he found the bone. Rather, he was looking into the diet and nutrition of the people who lived in the Lower Pecos region of Texas between 1,000 and 10,000 years ago. "It just so happens this person who lived 9,400 years ago was eating dog," Belknap said.

Belknap and other researchers from the University of Maine and the University of Oklahoma's molecular anthropology laboratories, where the DNA analysis was done, have written a paper on their findings. The paper was published in the American Journal of Physical Anthropology. For his research, Belknap---who does not own a dog himself---had fecal samples shipped to him that had been unearthed in 1974 and 1975 from an archaeological site known as Hinds Cave and kept in storage at Texas A&M University. The fragment is about six-tenths of an inch long and three- to four-tenths of an inch wide, or about the size of a fingernail on a person's pinkie.

Belknap and a fellow student identified the bone as a fragment from where the skull connects with the spine. He said it came from a dog that probably resembled the small, short-nosed, short-haired mutts that were common among the Indians of the Great Plains.Judging by the size of the bone, Belknap figures the dog weighed about 25 to 30 pounds. He also found what he thinks was a bone from a dog foot, but the fragment was too small to be analyzed. Other archaeological digs have put dogs in the U.S. dating back 8,000 years or more, but this is the first time it has been scientifically proved that dogs were here that far back, he said.

Darcy Morey, a faculty member at Radford University who has studied dog evolution for decades, said a study from the 1980s dated a dog found at Danger Cave, Utah, at between 9,000 and 10,000 years old. Those dates were based not on carbon-dating or DNA tests, but on an analysis of the surrounding rock layers. "So 9,400 years old may be the oldest, but maybe not," Morey told AP in an e-mail. Morey, whose 2010 book, "Dogs: Domestication and the Development of a Social Bond," traces the evolution of dogs, said he is skeptical about DNA testing on a single bone fragment because dogs and wolves are so similar genetically.

Belknap said there may well be older dogs in North America, but this is the oldest directly dated one he is aware of. For many years, researchers thought that dog bones from an archaeological site in Idaho were 11,000 years old, but additional testing put their age at between 1,000 and 3,000 years old, he said. "If there's one thing our discovery is showing it's that we can utilize these techniques and learn a lot more about dogs in the New World if we apply these tests to all these early samples," he said.

The earliest dogs in North America are believed to have come with the early settlers across the Bering land bridge from Asia to the Americas 10,000 years ago or earlier, said Wayne. It doesn't surprise Belknap that dogs were a source of food for humans. A lot of people in Central America regularly ate dogs, he said. Across the Great Plains, some Indian tribes ate dogs when food was scarce or for celebrations, he said. "It was definitely an accepted practice among many populations," he said.

Theories on Dog Domestication

Humans and wolves or proto dogs came together perhaps because they traveled in groups of about the size, inhabited the same areas and hunted the same prey and were able to help each other: with their sensitive noses dogs were good at locating prey, with their tools and weapons and skills early humans were good at killing large animals. It seems likely that wolves or proto dogs lurked around early human camps.

Offering a scenario of how dogs and humans came together Rudyard Kipling wrote in Just So Stories in 1912: "The Woman picked up a roasted mutton-bone and threw it to Wild Dog, and said, “Wild Dog,” and said, 'Wild Thing out of the Wild Woods, taste and try.' Wild Dog gnawed the bone, and it was more delicious than anything he had ever tasted, and he said, 'O my Enemy and Wife of my Enemy, give me another.'..,"The Woman said, 'Wild Thing out of the Wild Woods, help my Man to hunt through the day and guard this cave at night, and I will give you as many roast bones and you need."

Some scholars believe early humans adopted wolf pups. Some say early pets were orphaned animals that were found and kept in camps and perhaps even milk from the breast. Others believe that dogs domesticated themselves by scavenging garbage dumps and succeeding generation became less fearful of humans. The animals, perhaps attracted by the smell of meat, approached early human camps. The humans offered them food, the animals hung around and a bond was established that was passed to later generations, with natural selection favoring those less aggressive and better at begging for food. The submissive behavior that subordinate dogs express to dominate dogs and puppies show their mother was extrapolated from dogs to humans.

Study of the First Domesticated Dogs

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dogs in ancient Egypt
Jarrett A. Lobell and Eric Powell wrote in Archaeology magazine, “Just how and when the species first became recognizably "doggy" has preoccupied scientists since the theory of evolution first gained widespread acceptance in the 19th century. The idea that dogs were domesticated from jackals was long ago discarded in favor of the notion that dogs descend from the gray wolf, Canis lupus, the largest member of the Canidae family, which includes foxes and coyotes. While no scholars seriously dispute this basic fact of ancestry, biologists, archaeologists, and just about anyone interested in the history of dogs still debate when, where, and how gray wolves first evolved into the animal that is the ancestor of all dog breeds... Were the first dogs domesticated in China, the Near East, or possibly Africa? Were they first bred for food, companionship, or their hunting abilities? The answers are important, since dogs were the first animals to be domesticated and likely played a critical role in the Neolithic revolution. Recently, biologists have entered the debate, and their genetic analyses raise new questions about when and where wolves first developed into what we today recognize as dogs.[Source: Jarrett A. Lobell and Eric Powell, Archaeology magazine, September/October 2010]

The archaeological record suggests dogs were domesticated in multiple places at different times, but in 2009, a team led by Peter Savolainen of the Royal Institute of Technology in Stockholm published an analysis of the mitochondrial DNA of some 1,500 dogs from across the Old World, which narrowed down the time and place of dog domestication to a few hundred years in China. "We found that dogs were first domesticated at a single event, sometime less than 16,300 years ago, south of the Yangtze River," says Savolainen, who posits that all dogs spring from a population of at least 51 female wolves, and were first bred over the course of several hundred years. "This is the same basic time and place as the origin of rice agriculture," he notes. "It's speculative, but it seems that dogs may have first originated among early farmers, or perhaps hunter-gatherers who were sedentary."

In 2010 a team led by biologist Robert Wayne of the University of California, Los Angeles, showed that domesticated dog DNA overlaps most closely with that of Near Eastern wolves. Wayne and his colleagues suggest that dogs were first domesticated somewhere in the Middle East, then bred with other gray wolves as they spread across the globe, casting doubt on the idea that dogs were domesticated during a single event in a discrete location. Savolainen maintains that Wayne overemphasizes the role of the Near Eastern gray wolf, and that a more thorough sampling of wolves from China would support his team's theory of a single domestication event.

University of Victoria archaeozoologist Susan Crockford, who did not take part in either study, suspects that searching for a single moment when dogs were domesticated overlooks the fact that the process probably happened more than once. "We have evidence that there was a separate origin of North American dogs, distinct from a Middle Eastern origin," says Crockford. "This corroborates the idea of at least two 'birthplaces.' I think we need to think about dogs becoming dogs at different times in different places."

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tree of ancient dog breeds

As for how dogs first came to be domesticated, Crockford, like many other scholars, thinks dogs descend from wolves that gathered near the camps of semi-sedentary hunter-gatherers, as well as around the first true settlements, to eat scraps. "The process was probably driven by the animals themselves," she says. "I don't think they were deliberately tamed; they basically domesticated themselves." Smaller wolves were probably more fearless and curious than larger, more dominant ones, and so the less aggressive, smaller wolves became more successful at living in close proximity to humans. "I think they also came to have a spiritual role," says Crockford. "Dog burials are firm evidence of that. Later, perhaps they became valued as sentries. I don't think hunting played a large role in the process initially. Their role as magical creatures was probably very important in the early days of the dog-human relationship." [Source: Jarrett A. Lobell and Eric Powell, Archaeology magazine, September/October 2010]

Early Development of Dogs and Dog Breeds

Early dogs were smaller and the had relatively smaller snouts than wolves. When dogs were first domesticated their snouts and brain cases changed shape. Over time dogs developed tame dispositions. Their teeth and skulls grew smaller as they no longer needed to bring down large prey. Their brains became smaller as their diet switched from meat to human garbage (brains require a lot of calories and protein for growth and maintenance).

Early dogs were used for hunting and consumed for food. They also likely proved themselves useful by eating garbage, warning humans of danger and keeping people warm. In the Middle East dogs were used for hunting and herding wild goats and sheep and later used to herd domestic version of these animals.

Early dogs were medium size and resembled the skittish brown dogs found meekly scavenging around Third World villages. It is believed that the earliest breeds emerged as early people raised dogs that were good at things like guarding and hunting. Environment was also important. In cold climates, large dogs with thick coats have better chances at survival and reproduction than small, short-haired varieties.

Later humans began crossbreeding dogs with desirable characteristics that gave birth to the breeds we know today. In the mid 1800s, kennel clubs were established that officially recognized breeds and encouraged the development of new breeds. Most recently created breeds were created for their appearance.

Variety of Dog Breeds

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dog mummies
There are currently about 420 breeds of dogs. The oldest breed, the saluki, is thought to have emerged in 329 B.C. The most ancient dogs based on DNA evidence are the dingo, New Guinea singing dog, African basenji and greyhound.

All dogs have the same bones. The difference between the sizes and shapes of dogs is largely attributed to the fact that genes that affect the development of the fetus and puppy greatly alter a dog's final shape. The heads of puppies have different proportions than the heads of adult dogs and the way these proportions grow affect the way a dog looks. A greyhound, for example, has a long, slender snout because its nose starts growing early. A bulldog has short nose because the growth starts late.

The fact that dogs have 78 chromosomes (compared to 46 for humans) creates more opportunities for variation and enables these variations to develop relatively quickly. National Geographic described one man who wanted to develop a tail-less boxer. He crossed a boxer with a tail-less Welsh Corgi and took the tail-less offspring that looked most like boxers and mated them with other boxers. Eight years and four generations later he produced tail-less boxers that were winning show events.

Dog Characteristics and Behavior

All dogs wag their tails, have multicolored coats and have the ability to be trained. No one has come up with with a satisfactory answer to the question of why dogs bark.

Dogs and wolves share similar behaviors and means of communications. Tail waging is a sign a friendship. Bowing is an invitation to play. When a dog lays on it back and exposing the stomach it is making itself vulnerable as a display of trust and affection. Licking is an expression of affection and submission. Wolf puppies lick their mothers to encourage them to regurgitate food.

Dogs also express submission by lowering their body and head, tucking back their ears, diverting their eyes, and tucking their tail between the legs. Anger and aggression is expressed by holding the tail high, baring the teeth and staring directly ahead.

After mating the male dog removes his forelegs from around the female's back but his penis often remains inside her. Sometimes the pair will remain stuck for a half an hour or more. This is because just before ejaculations the base of the penis swells into a bulb and is unable to withdraw.

Dog Intelligence

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Saluki
A border collie named Rico appeared in a German television game show in 2001. He knew the names of 200 toys and the easily up the names of new objects and was so smart researchers at the Max Planck Institute of Evolutionary Anthropology in Leipzig decided to study him. Their research showed that Rico could learn and remember words as quickly as a human toddler---which can acquire about 10 words a day. [Source: Virginia Morell, National Geographic, March 2008]

After checking out reports from hundreds of other dog owners that claimed their pets had advanced language abilities, only two---both border collies---were as clever as their owners claimed. One of them, a dog living in Vienna---which the researchers named Betsy---had a vocabulary of more than 340 words. She showed intelligence at an early age: at ten weeks she could sit on command and after that picked up object names such as a ball, paper, box, kety and rope, and dozens more. As of 2008 she knew 15 people by name and was able to link photographs with object pictured in the photographs. Her owner told National Geographic, “She’s a dog in a human [pack]. We’re learning her language , and she’s learning ours.”

Juliane Kaminski, a cognitive psychologist who worked with both Rico and Betsy, told National Geographic , “Even our closest relatives, the great apes, can’t do what Betsy can do---hear a word only once or twice and know that the acoustic pattern stands for something...maybe these collies are especially good at it because they’re working dogs and highly motivated, and in their traditional herding jobs, they must listen very closely to their owners.”

The first dog to be cloned was an Afghan cloned in 2005 by South Korean researchers.

Image Sources: Wikimedia Commons

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Lonely Planet Guides, Library of Congress, U.S. government, Compton’s Encyclopedia, The Guardian, National Geographic, Smithsonian magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Wall Street Journal, The Atlantic Monthly, The Economist, Foreign Policy, Wikipedia, BBC, CNN, and various books, websites and other publications.

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© 2008 Jeffrey Hays

Last updated May 2016

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