Dog Family Tree Traced Back 2 Million Years
Fossils for a scrappy, Italian canine that lived 2 million years ago are helping researchers to better understand the evolution of wolves and dogs.
A new cache of extremely well preserved, prehistoric canine fossils is shedding light on dog and wolf ancestors from 2 million years ago to today.
The fossils, described in the latest issue of the Journal of Mammalian Evolution, date to that early period and belonged to a scrappy canine carnivore known as Canis etruscus that lived near Rome, Italy.
"Canis etruscus appeared approximately 2 million years ago and is the oldest European species referred to in the genus Canis," lead author Marco Cherin told Discovery News, adding that this species "was considerably smaller than the modern wolf."
"We can suppose that it was a social dog, as most of the living species of similar size," continued Cherin, who is a researcher at Perugia University's Department of Earth Sciences. "Hunting in packs, Canis etruscus could have preyed on small to medium-sized animals."
The prey of this carnivore, which looked like a cross between a German shepherd and a wolf, would have included animals such as ancient relatives of deer and pigs. They were all common at the site: Pantalla, Italy.
This apparent mother of all dogs in Europe likely gave rise to another member of the dog/wolf family tree, Canis mosbachensis, about 1 million years ago. Canis mosbachensis, in turn, is considered to be a direct ancestor of modern wolves.
Until recently, it was thought that dogs were domesticated from the gray wolf, but a separate study earlier this month countered that popular belief.
"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 of UCLA, who was co-senior author of the study, told Discovery News.
That animal went extinct thousands of years ago and, as of now, remains unknown.
What is known about dog history is that the first canines came from North America, Cherin said. The earliest documented species from the genus Canis was Canis lepophagus, aka the "hare-eating wolf." Like the prehistoric canine from Italy, it was relatively small and had a narrow head.
Canines spread to Asia and then to Europe. It was in Eurasia at least 780,000 years ago that a dog relative might have encountered a member of our genus.
Eudald Carbonell, a professor at the University of Rovira and Virgili, told Discovery News that fossils of Homo antecessor -- an extinct human that looked a lot like us -- were found with fossils of Canis mosbachensis in Spain.
Could this very early human have enjoyed the companionship of the dog/wolf relative, or was the latter considered to be good eats or a predator? The fossil record so far, unfortunately, does not have those answers.
Carbonell and his team did find evidence for cannibalism -- for nutritional purposes -- among Homo antecessor individuals, so it's likely that this early, hungry human hunted the dog and wolf relative.
As the human population continued to expand and evolve in Europe and Asia, people discovered how valuable canines could be for security, hunting, companionship and more, resulting over time in the domestication of dogs. That moment of doggy revelation might have even happened in Italy, since recent DNA evidence suggests the first domesticated dogs were from Europe.
Marina Sotnikova of the Geological Institute of Russian Academy of Sciences told Discovery News that the fossils discovered in Italy are "very interesting" and "allow for a more detailed study of this group of carnivores."
Members of the dog and wolf family tree.
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.
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.