Dogs Not as Close Kin to Wolves as Thought
Baccharus/Wikimedia Commons/UK Wolf Conservation Trust
A dog, left, and gray wolf, right, both howling.
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.
A widely held belief is that dogs evolved from gray wolves, but a new study finds that the common ancestor of dogs and wolves went extinct thousands of years ago.
What's more, the extensive DNA analysis -- published in the latest PLoS Genetics -- found that dogs are more closely related to each other than to wolves, regardless of their geographic origin. The genetic overlap seen today between dogs and wolves is likely then due to interbreeding after dog domestication.
"The common ancestor of dogs and wolves was a large, wolf-like animal that lived between 9,000 and 34,000 years ago," Robert Wayne, co-senior author of the study, told Discovery News. "Based on DNA evidence, it lived in Europe."
For the study, Wayne, a professor in UCLA's Department of Ecology and Evolutionary Biology, and his colleagues generated genome sequences from three gray wolves: one each from China, Croatia and Israel, representing three regions where dogs are believed to have originated.
The researchers also produced genomes for two dog breeds: a basenji, a breed that originates in central Africa, and a dingo from Australia. Both locations have been historically isolated from modern wolf populations. The scientists, co-led by John Novembre, additionally sequenced the genome of a golden jackal to serve as an example representing earlier divergence.
Instead of all three dogs being closely related to one of the wolf lineages, or each dog being related to its closest geographic counterpart, the DNA points to the dogs having descended from an unknown wolf-like ancestor.
Wayne explained that many animals went extinct during the late Pleistocene (20,000 to about 12,000 years ago), which experienced a global ice age. Coincidentally -- or maybe not -- modern humans also became more prevalent in Europe at this time. It could be that humans led to the extinction of some animals at that time, but the jury is still out on the issue.
A dog, left, and gray wolf, right, both howling.Baccharus/Wikimedia Commons/UK Wolf Conservation Trust
Dogs clearly were not in that group. Wayne now believes that dog and human interactions went through three primary stages:
1- Hunter gatherers, possibly even Neanderthals, interacted with dogs, probably benefiting from their presence. For example, dogs might have kept other, more dangerous, carnivores out of the way. They could have also helped with hunting.
2- With the emergence of agriculture, dogs lived near humans and adapted to an agricultural diet. Prior studies have found that dogs in such regions possess higher numbers of amylase genes that help to digest starch. Wolves have these genes too, the scientists found, but usually not in such high amounts.
3- In more recent history, humans have selectively bred dogs, which has dramatically changed the appearance, behavior and other attributes of dogs.
Throughout this overall period of time, interbreeding with wolves occurred, and still happens, further complicating the genetic relationship between wolves and dogs.
Elaine Ostrander, an investigator at the National Human Genome Research Institute, told Discovery News, "This paper is exciting for students of canine history as well as dog owners because it clarifies the events leading up to dog domestication. We now know that it was not a single event, but several, which makes sense when we think about the extraordinary variation that we seen in modern dogs."
She added, "We also know that the critical intermediate -- the dog/wolf -- is not alive on the planet today. However we don't know why. Did is suffer from some infectious disease, a plague of sorts? Was it killed off by other animals? Did it starve?"