An international collaboration of 81 scientists published in the journal Nature a tightly argued, detailed case for dogs having originated in at least two places before the Last Glacial Maximum around 28,000 years ago.
The prevailing view is that the origin of dogs took place only once, although where that occurred is subject to fierce argument. In its June 29 paper, “Grey wolf genomic history reveals a dual ancestry of dogs,” the team made the case that there were at least two domestications and possibly more.
The researchers reached their conclusion by analyzing the genomes from DNA extracted from 72 ancient wolves. They compared these genomes with those of both ancient and modern dogs. Such comparisons provide insights into the timing of genetic mutations believed to be extensive enough to define groups of animals as separate species.
The team identified one gene, IFT88, that seems responsible for the craniofacial structure of canids, giving dogs the broader muzzle and other characteristic morphologies that separate them from wolves. Another gene involved in olfaction also differentiated the dog lineage from that of wolves.
Finding out that these genetic splits emerged long before dogs first appeared in Siberia, a currently favored point of origin indicates breed, dogs, and wolves had begun to follow different evolutionary paths well before the Last Glacial Maximum.
While interesting in terms of supporting the view—on which the authors didn’t dwell—that the wolf/dog split occurred earlier than most experts believe, the work failed across to address the more significant problem of how such genetic change became widespread space and time.
Unfortunately, the paper is based on the notion that wolves are humans’ natural-born enemies who somehow underwent a conversion experience to become our best friends. As long as people studying this field persist in basing their arguments on that wrong and distorted view, I fear they will never get it right.
Meanwhile, PLOS Genetics published an article in June describing the genetic history of a rare group of dogs that herd sheep throughout Patagonia, in southernmost South America.
This rugged country hosts a landrace of dogs, a group that has evolved to match its role in society. These “purpose-bred” animals, known in Spanish as the Barbucho or Ovejero Magallánicoare recognized by no kennel club in the world.
The Ovejero Magallánico in Patagonia is derived from British herding dogs.
Source: Gernikatar/Wikimedia Commons
The geneticists found that these dogs are closest to the progenitors of modern British herding dogs.
No one knows exactly when herding dogs arose in the history of dogdom. There have been suggestions that they may have helped people domesticate goats, sheep, and cows, as wherever remains of dogs have been found those animals were located.
Sometimes they were paired with big guard dogs; other times, they worked with sheep in the absence of such guardians. In much of the world, there have been two schools of animal care, the one relying on the guard dog to protect but not startle the sheep, and the more active style which uses the dogs to move the animals from the barn to the pasture and back.
Each type had its different proponents; As the breed clubs began to form, people took these rough purpose-bred dogs and refined them to match a standard appearance. In the process, the newly minted breeds were praised for their intelligence, sagacity, general helpfulness, and courage, while the rough cur was dismissed as dirty and not very bright. Cur became a slur directed toward any mixed breed.
Fortunately, the Patagonian sheepdog has to date, escaped that fate. The authors explained why by showing that the progenitors of the current dogs of Patagonia traveled with their migrating shepherds from the British Isles to the Falkland Islands, Argentina, and Chile.
The current dogs trace their lineage directly to the original bearded collies, border collies, and kelpies who arrived on the continent. What makes this paper so interesting is that it uses the genetics of the animals to track their movements with their people.
The researchers also showed that the infusion of border collie genes to herding dogs in the northern portion of Patagonia might be due to the popularity of purebred border collies in this century.
This paper focused purely on the Patagonian dogs and their possible British origin. It would be interesting to consider other landrace sheep herding dogs, such as those found in Romania. That kind of study might take us even closer to the origins of these all-around dogs.