Study Shows Small Dogs Evolved in Middle East

Source: Sciencemag.org, Feb 24, 2010

Mexico may claim the Chihuahua, and Tibet the shih tzu. But a new genetic study indicates that all small dogs have their origins in the Middle East.

The origin of the domestic dog is a hot topic in evolutionary biology. Scientists agree that today’s Fidos came from the domestication of the gray wolf, but they are at odds over where this took place. Previous genetic studies focusing on mitochondrial DNA—inherited only from the mother—have suggested that modern domestic dogs are descended from animals that lived in East Asia between 5000 and 16,000 years ago. But archaeological excavations in Europe and the Middle East have found remains of what appear to be domestic dogs dating back as far as 31,000 years.

Now, a team led by evolutionary geneticist Melissa Gray of the University of California, Los Angeles, has examined nuclear DNA to fill in a crucial piece of the puzzle. The researchers took samples of blood, tissue, or saliva from three populations: large domestic dogs (those weighing more than 30 kilograms), small dogs (weighing less than 9 kilograms), and wild wolves, foxes, and coyotes from around the world. They then looked at a gene called insulin-like growth factor 1 (IGF1). All canines, wild or domestic, have some form of this gene—precisely which form is strongly associated with the size of an animal’s skeleton.

The team found that the version of IGF1 carried by all small dogs is found in very few large dogs and no wild canines. But a very similar form of the gene is found in gray wolves from the Middle East. That means that this region is probably the birthplace of the common ancestor of all the world’s small dogs. Because they all carry the same variant, it is extremely unlikely that small body size evolved more than once. And for the gene to have had time to spread all over the world, it must have evolved shortly after dogs were first domesticated.

Gray emphasizes that the study, published today in BMC Biology, doesn’t necessarily mean that dogs were first domesticated in the Middle East. But it’s a “strong indication” that that region “has played a significant role in the early history of domestic dogs.” The authors note that archaeologists have found remains of small dogs dating to 12,000 years ago in the area. There are older sites in Europe and Russia, but they contain larger dogs. She says humans living in small agricultural communities may have deliberately bred small dogs because they ate less and could be kept in small spaces.

Adam Boyko, a geneticist at Stanford University in Palo Alto, California, who specializes in the evolution of the domestic dog, is impressed by the study. “This really pokes a hole in the argument of this relatively simple domestication in East Asia, … which is what people have been arguing based on mitochondrial DNA,” he says.

Study: Wolves beat dogs when it comes to logic

Source: MSNBC.com, September 3, 2009

In experiments, dogs followed human clues despite seeing better solutions

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Wolves do better on some tests of logic than dogs, a new study found, revealing differences between the animals that scientists suspect result from dogs’ domestication.

In experiments, dogs followed human cues to perform certain tasks despite evidence they could see suggesting a different strategy would be smarter, while wolves made the more logical choice based on their observations.

In fact, dogs’ responses were similar to human infants, who also prioritize following the example of adult humans.

During the tests, a researcher would repeatedly place an object in Box A and allow the subjects to find it. When the experimenter then switched and put the object in Box B, human babies and dogs were confused and continued to search for it in the first box. Wolves, however, easily followed the evidence of their eyes and located the object in Box B.

The finding could help scientists learn more about the evolution of social behavior, not just in dogs but in humans as well.

Human cues
The differences reflect an emphasis on different learning styles, scientists say.

“I wouldn’t say one species is smarter,” said Adam Miklosi of Eötvös University in Hungary, co-author of a paper describing the results in the Sept. 4 issue of the journal Science. “If you assume an animal has to survive without human presence, then wolves are smarter. But if you are thinking that dogs have to survive in a human environment where it’s very important to follow the communications of humans, then in this aspect, dogs are smarter.”

The researchers think the differences between the dog and wolf subjects — both of which had been raised in human captivity in these experiments — arises from genetic traits that have been bred into dogs over 10,000 years of domestication by humans. Wolves and dogs diverged from a common ancestor at least 15,000 years ago, scientists think.

“This finding provides strong support for the domestication hypothesis, by again showing striking dog-wolf differences, and striking dog-human convergences — in this case, in a task with which most dogs have no previous experience,” Michael Tomasello and Juliane Kaminski, scientists from the Max Planck Institute for Evolutionary Anthropology in Germany who did not work on the new study, wrote in an accompanying essay in the same issue of Science.

Other experiments have noted that dogs are more attentive to the human voice and subtle vocal changes than wolves — another trait that likely results from domestication.

Dog-human connections
In some ways, domesticated animals resemble human infants because both learn primarily by following and listening to adult humans, rather than judging all new situations for themselves.

“When babies are young they are exposed to a relatively complex environment which is full of very complicated situations,” Miklosi told LiveScience. “Children are programmed to learn from the adult humans, especially when they can’t understand the logic behind the situation — like learning a language. What they have to do is go along with what adults are saying.”

Children are programmed to learn from their elders when it comes to crossing the street and other dangerous situations in which following their own curiosity and instincts are not the best learning mechanisms.

It is similar for domesticated dogs, which are bred to be able to follow human cues when it comes to situations like not eating food off the table, rather than following their own instincts to go for the chicken. This ability makes dogs easier to train — a key requirement for a domesticated species.

Even though the wolves used in the experiment were raised in captivity, their parents or their parents’ parents were wild, so the test wolves are not domesticated creatures with traits hard-wired into their genes over thousands of generations.

Social evolution
The point of the research is not just to learn about the domestication of dogs, but to use dogs and wolves as a test case for studying how social behavior can evolve, and especially how it may have evolved in humans.

“We see dog behavior and human behavior as a convergence,” Miklosi said. “Dogs became similar to humans because they had to live in a human social environment. This will tell us quite a lot about human social evolution.”

By studying how dogs learned to socialize with humans, scientists hope to understand more about how humans came to socialize with humans.

Interestingly, dogs and babies did react differently to one aspect of the experiment: When the human researcher was replaced by a new person, dogs forgot their lesson about Box A and followed their eyes instead. Infants, however, responded the same with multiple human teachers, continuing to trust the human over the visual evidence.

Dachshund survives wolf attack in South Range, MN

Source: DuluthNewsTribune.com, June 19, 2009

Jada is a 15-pound hero. The eight-year-old dachshund hurled herself at a wolf June 9 to save a fellow canine, Lana.

As the dogs’ owner, Dana Lundeen, tells it, she was sitting on the front porch of her South Range home that afternoon when first Lana, then Jada, ran barking around the house. Suddenly, she heard an awful bark. Rounding the corner of the house, she saw a wolf about 75 yards away.

As Lundeen watched, it kicked aside the one-year-old Lana and grabbed Jada in its mouth. She ran toward them, yelling.

“I was screaming my lungs out, hoping he would drop her and he did,” Lundeen said.

As the wounded dog ran back toward the house, she said, the wolf took a few steps in Lundeen’s direction, than padded away.

“It happened so fast,” she said. “I was more worried about my dog than anything.”

Lundeen wrapped the bleeding dog in a blanket and called her 17-year-old son, Devin, home from Northwestern High School to help.

“I didn’t know if I’d have to shoot her,” Lundeen said. “I mean, her stomach’s hanging out. [Devin] says ‘Well, Mom, is she alive?’ Well, yeah. He said, ‘Well, then there’s hope.’ ”

They drove to Superior Animal Hospital, where the dachshund spent 3½ hours in surgery.

“They are awesome people there,” Lundeen said.

The wounds were similar to those seen when a larger dog attacks a smaller one, said veterinarian Bob McClellan. “The internal wounds are 10 times worse than what it looks like from the outside.”

Jada suffered crushed ribs, a spleen split in two, a collapsed lung and a left kidney that had been pulled away from the abdominal wall, he said. But the veterinarian was able to repair her, inside and out. After that, it was up to the dachshund.

“The dog’s a tough little dog,” McClellan said. “She hung in there.”

Sunday, she returned home to South Range.

“She’s full of many, many staples,” Lundeen said, affectionately calling the dog “Frankenweinie.”

Lana was uninjured.

Born and raised in South Range and living on Lundeen Road off County Highway V since October, Lundeen said she’s seen deer, coyotes, foxes, geese and more animals cross the 64-acre property regularly. Still, the wolf came as a surprise.

A winter 2008 survey by the Wisconsin Department of Natural Resources puts the number of wolves in the state between 626 to 662, nearly 100 more than the previous year. Most of them live in the north.

“Douglas County has some of the highest density of wolf populations in the state,” said Adrian Wydevan, a DNR mammal ecologist based out of Park Falls

“They are mostly shy, living out their lives in the forest,” he said.

But sometimes not. “Last year, we had seven cases of dogs attacked near people’s homes,” he said. One died, the others were only injured. That was mostly due to owners who were close enough to scare the wolves away.

McClellan noted that the amount of damage the wolf did to Jada with one bite was incredible.

“If the wolf had had a second bite, the dog would have been done,” he said. “Fortunately, Dana was there when it happened.”

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