A team of Swedish and Chinese researchers say they have pinpointed — at least more than it has been pinpointed up to now — the place where, 16,000 years ago, the wolf was tamed and evolved into the dog.
It was in China, on the southern shores of the Yangtze River, they say.
Their findings are contained in an article in the latest issue of scientific journal Molecular Biology and Evolution.
“For the first time … it is possible to provide a detailed picture of the dog, with its birthplace, point in time, and how many wolves were tamed,” says Peter Savolainen, a biologist and member of the research team at the Royal Institute of Technology (KTH) in Stockholm.
Together with Swedish colleagues and a Chinese research team, Savolainen has made a number of new discoveries about the history of the dog — including the most specific date and birthplace yet offered.
“Our earlier findings from 2002 have not been fully accepted, but with our new data there will be greater acceptance. The picture provides much more detail,” says Savolainen.
Savolainen said the research indicates that the dog has a single geographic origin but descends from a large “large number of animals – at least several hundred tamed wolves, probable even more,” according to Science Daily.
The theory that the domestic dog originated in East Asia was challenged earlier this month by an international group of researchers who say African dogs are just as genetically diverse.
That research, based on analyzing blood samples from dogs in Egypt, Uganda and Namibia, shows the DNA of dogs in African villages is just as varied, indicating it could have been where wolves made the transition to become dogs.
(Photo: Science Daily press release)
Posted by jwoestendiek September 2nd, 2009 under Muttsblog.
Tags: africa, animals, china, chines, dog, dogs, east asia, evolution, origin, peter savolainen, pets, research, royal institute of technology, science, stockholm, study, sweden, wolf, wolves, yangtze
Scientists in Sweden have tracked down the source of sensory ataxic neuropathy (SAN) — a recently identified neurological disorder in golden retrievers.
The disease strikes goldens in puppyhood, causing them to move in an uncoordinated manner and have sensory deficits.
The researchers were able to trace back all affected offspring on the maternal side, over more than 10 generations, to a female that lived during the 1970s, confirming that SAN is caused by a mutation in the mitochondrial DNA.
The study by the Swedish University of Agricultural Sciences, Uppsala University and the Karolinska Institutet was published May 29 in the journal PLoS Genetics.
The researchers showed that about five percent of the golden retriever population in Sweden carries the mutation causing SAN — and that, with proper screening by breeders, the disorder could be eliminated.
“This is a good example of how a close collaboration between clinicians and geneticists led to a rapid detection of a harmful mutation that can now be eliminated from this dog population to reduce suffering and disease,” said co-author Karin Hultin Jäderlund.
Posted by jwoestendiek June 2nd, 2009 under Muttsblog.
Tags: detection, disease, disorder, dna, generations, genetics, golden retriever, maternal, mitochondrial, mutation, san, science, screening, sensory ataxic neuropathy, sweden, swedish, swedish university of agricultural sciences
According to a report in the London Telegraph, the researchers say the change has taken place over the course of just a few generations.
While 19th century dogs were selected for breeding based on their strength and skills — such as guarding homes, retrieving quarry or watching over livestock — today’s dogs are more likely to be chosen strictly for their appearance. As a result, the researchers say, the are less responsive to commands and not as alert or attentive.
“Modern breeding practices are affecting the behavior and mental abilities of pedigree breeds as well as their physical features,” said Kenth Svartberg, an ethologist from Stockholm University and author of the research report.
Dr. Svartberg tested 13,000 dogs on characteristics such as sociability and curiosity to help him rate 31 different breeds. He found that those bred for appearance, and especially for shows, displayed reduced ability levels. He also found that attractive appearance was often linked with introversion and a boring personality.
The worst affected working breeds were smooth collies, once a herding dog, and Rhodesian ridgebacks, which were used for hunting.
(Image from My Dog’s Brain, by Vermont artist Stephen Huneck)
Posted by jwoestendiek February 2nd, 2009 under Muttsblog.
Tags: agile, alert, appearance, attentive, breeders, breeding, breeds, dogs, dumber, looks, my dog's brain, practices, purebreds, research, scientists, skills, standards, stephen huneck, stockholm university, sweden, swedish