University of Manchester
A pointer named “Major” is identified as the first known example of a modern dog. A description of the dog was found in a now-obscure 1865 edition of a Victorian journal called The Field. It marks the earliest reported dog breed based on physical form and pedigree. “The invention of ‘breed,’ physically and imaginatively, still shapes how we see and think about dogs today,” Michael Worboys, Director of the University of Manchester’s Centre for the History of Science, Technology and Medicine, told Discovery News. Worboys and his team found the information concerning “Major” while preparing a new museum exhibit on dogs.
The first domestication of dogs was thought to have taken place 31,680 years ago -- but new research suggests the skull in question likely belong to a wolf. This particular specimen was found with a still-visible mammoth bone in its mouth.
The paleolithic dog remains resembled a modern Siberian husky, but suggest an animals that was significantly larger. Today, the Siberian husky, Samoyed and Alaskan malamute breeds are all closely related. "The most remarkable difference between these dogs and recent dog breeds is the size of the teeth,” paleontologist Mietje Germonpré said. Other early dog breeds, with a focus on the U.K., are featured in the museum exhibit curated by Worboys and his team. Entitled “Breed: The British and Their Dogs,” the exhibit runs at the University of Manchester museum through April 14.
Another team of researchers, led by Heidi Parker of the National Human Genome Research Institute, used DNA analysis to determine the genetic relationships of numerous dog breeds. One such ancient breed is the Afghan hound. As its name suggests, it's native to the Middle East. It’s one of the oldest dog breeds in existence, and was originally used for hunting hares and gazelles.
Parker and her team found that Akitas are yet another ancient breed. These dogs originated in Asia and are genetically similar to chow chows. The breed was not included in the first dog show. “The first dog show was in 1859 when only two varieties were shown: pointers and setters,” Worboys said. It had nothing to do with the handsome Akita’s looks, as he explained that the first dog show was “for gun dogs only.”
The sleek-bodied saluki comes from Iran, where its distant ancestors might have once lived near the earliest farmers from the Fertile Crescent. Dogs in this region evolved the ability to eat a starch-rich diet around 12,000 years ago. “Our findings show that it was crucial to early dogs to be able to thrive on a diet rich in starch,” Uppsala University’s Erik Axelsson, who led a related study, told Discovery News. “That indicates that dog domestication may be linked to the development of agriculture. It is possible that dogs may have been domesticated independently at locations where agriculture developed early, such as the Fertile Crescent and China.”
One of the most ancient dog breeds native to the United States is the Alaskan malamute. The DNA study found that they are genetically similar to Siberian huskies. This large, muscular dog was used -- and still is -- for pulling sleds, hauling freight by other means, and for additional work tasks.
The basenji is “an ancient African breed,” according to Parker and her colleagues. While “Major” the pointer is the first documented modern breed of dog, the basenji is arguably the first dog to be heavily bred by humans. Although this dog hails from central Africa, paleontologists believe its wolf ancestors originally came from eastern Asia.
Remigiusz Józefowicz/Wikimedia Commons
In China, the chow chow is affectionately referred to as Songshi Quan, meaning “puffy-lion dog.” It is genetically close to the Akita, also from Asia. It represents yet another early breed.
Of the four most ancient known Asian dog breeds, the shar-pei was the first to diverge from a wolf ancestor, suggesting it is the oldest known Asian breed. This dog is famous for its deep wrinkles and blue-black tongue. Mutations of the same gene that causes wrinkles in these dogs can also cause wrinkling of human skin.
An inbred dog that lived about 11,000 years ago was ground zero for a form of canine cancer that spread via mating and is afflicting dogs around the world to this day, according to new research in the journal Science.
The cancer-canine transmissible venereal tumor (CTVT) is one of only two known transmissible cancers. The other is found among afflicted Tasmanian Devils. CTVT causes genital tumors and can be fatal, particularly in older dogs or those suffering from an immune system deficiency.
The cancer spread, in part, because it wasn’t always fatal. If afflicted dogs died before mating, the disease wouldn’t spread across generations.
To track down the cancer’s source, Elizabeth Murchison, from the Wellcome Trust Sanger Institute and the University of Cambridge, and her colleagues sequenced the genome for CTVT. It is now believed to be the world’s oldest continuously surviving cancer.
“The genome of this remarkable long-lived cancer has demonstrated that, given the right conditions, cancers can continue to survive for more than 10,000 years despite the accumulation of millions of mutations,” Murchison said in a press release.
Remarkably, the genome of the cancer carries at least 2 million mutations. This is many more than in most human cancers. (Most of those have anywhere from 1,000 to 5,000 mutations.) For the study, the researchers used one type of mutation, known to accumulate steadily over time as a “molecular clock,” to estimate that the cancer first arose 11,000 years ago.
The genome also contains clues about what the prehistoric, ground-zero dog looked like. The researchers think it resembled an Alaskan malamute or husky. It likely had a short, straight coat that was grey/born or black.
The genetic sequence could not determine if the dog was male or female, but the scientists could determine that this dog was inbred. That might have led to the cancer arising in the first place, but the first appearance of the disease is still a mystery at this point.
“We do not know why this particular individual gave rise to a transmissible cancer,” said Dr Murchison. “But it is fascinating to look back in time and reconstruct the identity of this ancient dog whose genome is still alive today in the cells of the cancer that it spawned.”
She thinks the cancer first existed in an isolated population, before rapidly spreading around the world in recent centuries.
“It spread around the world within the last 500 years,” she explained, “possibly carried by dogs accompanying seafarers on their global explorations during the dawn of the age of exploration.”
“The genome of the transmissible dog cancer will help us to understand the processes that allow cancers to become transmissible,” said Sir Mike Stratton, senior author of the paper and director of the Sanger Institute. “We should be prepared in case such a disease emerged in humans or other animals.”
Photo: Alaskan husky. Credit: Randy Hausken, Wikimedia Commons