STUDY BARKS UP EVOLUTIONARY TREE A new DNA analysis of prehistoric and modern animals reveals our present-day doges are most closely related to an extinct species of European wolf.

By Monte Morin Los Angeles Times, November 14, 2013 When it comes to evolutionary debates, this one is a major dogfight. Since the time of Charles Darwin, scientists have argued over the origin of domesticated dogs, speculating wildly about how, when and where a toothy, flesh-eating beast was first transformed into man’s best friend. Some experts believe humans were naturally drawn to small, furry wolf pups, and seized them as novelties. Others suggest they were raised for slaughter by early agrarian societies. Yet another theory holds that early proto-dogs were enlisted as helpers by roving bands of hunters, long before humankind ever experimented with agricultural livestock. But the epic argument over what sparked the Big Bark may finally be drawing to a close. As researchers avail themselves of faster and cheaper DNA sequencing technology, experts are zeroing in on the time and place where dogs were welcomed into human society.

Ancient dog (Royal Belgian Institute of Natural Sciences) This skull fragment belonged to a Palaeolithic dog that lived 36,000 years ago near the Goyet cave in Belgium. Researchers believe the species represented by this fossil is from a species that was an ancient sister-group to all modern dogs and wolves, rather than a direct ancestor. Dogs, the authors argued, evolved from a now extinct species of European wolf that followed bands of nomadic or semi-nomadic humans who were hunting woolly mammoths and other large prey. Initially, the wolves sought out the carcasses and scraps of meat left behind by man, the authors suggest. Over time, these hang-around wolves began to fill a special role in human hunter-gatherer society, researchers say. “The initial interactions were probably at arm’s length, as these were large, aggressive carnivores,” said senior study author Robert Wayne, an evolutionary biology professor at UCLA. “Eventually though, wolves entered the human niche. ... Maybe they even assisted humans in locating prey, or deterred other carnivores from interfering with the hunting activities of humans.” From Europe, domesticated dogs spread across the Old World, and then to the Americas. However, the robust European wolf that got the fetch ball rolling left no other living descendants besides dogs. “Wolves living on the planet today are not the closest group to the ancestor of dogs,” Wayne said. Domestication debate Until recently, many archaeologists and biologists believed that dogs were first domesticated no more than 13,000 years ago, either in East Asia or the Middle East. A burial site in Israel contained the 12,000- year-old remains of an elderly man cradling a puppy. Archaeologists pointed to this find, as well as others, as evidence of a special, ancient bond between dogs and humans. Yet tracing the exact path of dog evolution has been extremely difficult. Ancient dog remains are hard to distinguish from wolf remains, and frequent interbreeding between dogs and wolves further complicate matters. Add to that mankind’s zealous breeding of the animals to enhance specific traits and behaviors and the genetic waters become very clouded. In fact, Darwin himself believed that the dizzying variety of existing dog breeds argued strongly that dogs must have had more than one wild ancestor. Genetic researchers today say this is most likely not the case, and that domesticated dogs evolved from one ancestor, in one region. There are those, however, who argue that Wayne and his colleagues are barking up the wrong genetic tree. Peter Savolainen, an associate professor of evolutionary genetics at Sweden’s Royal Institute of Technology, argues that evidence shows dogs were first domesticated in China, probably as a source of food. He pointed out that the paper lacks animal samples from the Middle East or China. “The only thing you’re looking at is European and Russian samples,” he said. “What can you tell really about anything? If you only have European samples, obviously you will find that Europe is the origin.” Wayne said he and his colleagues did not include samples from those areas because they were too recent, only about 7,000 or 8,000 years old. “That’s well after dogs were domesticated, so we’re kind of limited in that sense,” he said. Study authors said they hope to confirm their findings with additional testing of genetic material. In the meantime, experts are left to ponder this latest development, as well as the reason why scientists have argued so heatedly about the origin of dogs. “You might as well ask why,” Serpell said with a laugh. “People make up tremendously elaborate stories about the origin of our own species based on a few fossil remains here and there, or DNA from this individual or that individual. I guess we’re doing the same thing now to our dogs. ” http://www.latimes.com/science/sciencenow/la-sci-sn-dogs-domesticated-in-europe- 20131114,0,2657010.story?page=2#ixzz2mwVd2sjl