Original North American Dogs Descended From Siberian Populations

Leslie Hanson
July 9, 2018

A new study out this week in Science seems to better illuminate one of these detours.

The genetic analysis also showed the earliest American dogs - arriving some 9,000 years ago, a few thousand years after the first people showed up - dispersed across the continent.

Dozens of researchers collaborated for the expansive study. This human-canine partnership has been gleaned through bones: The earliest dog remains found in North America were buried almost 10,000 years ago in what is now IL.

Comparing the sequences with 145 mitochondrial genomes from other canid species resulted in a family tree with the so-called "precontact dogs" on a branch of their own, closely related to another ancient group from Zhokhov Island in Eastern Siberia. "The thought that there's actually a preserved signature of one of those early North American dogs that are extinct today in this tumor, which is just perpetuating it then forever, is very cool". "Although this cancer's DNA has mutated over the years, it is still essentially the DNA of that original founder dog from many thousands of years ago". Although there is intriguing evidence that during this time these dogs interbred with wild canids endemic in North America, like coyotes and grey wolves.

To come to this conclusion, researchers conducted the first ever comprehensive genome study of ancient canines, analyzing nuclear DNA, which comes from both parents, and mitochondrial DNA, which comes from the mother.

The dogs did not descend from North American wolves but rather from Siberia. Instead, these dogs shared an ancestor with the husky. But though this lineage thrived for centuries, it seems their fate was inextricably tied to the indigenous people who were killed by the Europeans.

The near-absence of pre-contact dog DNA in today's pooches shows that breeds often touted as the oldest in the Americas, such as chihuahuas, are actually Eurasian in origin, Perri said.

Scientists believe that ancient American dogs were wiped out by colonizers brought diseases to the American continent. While unsampled pockets of American dogs might still remain, what we've found so far suggests that they have been extensively replaced by European breeds.

The remains of a 10,000 year-old dog has proved key to solving an important canine conundrum: What happened to the dogs of ancient North America?

"The picture is not as clear as they want it to be", Peter Savolainen, an associate professor in Evolutionary Genetics at the Royal Institute of Technology in Stockholm, told Gizmodo.

Comparison of ancient and modern American dog genomes, however, demonstrated that these pre-contact American dogs rapidly disappeared following the arrival of Europeans and left little to no trace in modern American dogs. It also took a devastating toll on their pets.

The team suspected that epidemics and hunting might contribute to the purge of these pre-contact dogs.

Modern dogs, the study reveals, contain nearly no traces of those original dogs with one big exception: a cancer that is spread from dog to dog through mating, resulting in a malignant tumor.

An worldwide team of researchers says the only surviving legacy appears to be a cancer that afflicts dogs that arose from the cells of a dog that lived more than 8,000 years ago and has since spread to other canines around the world.

Other reports by Iphone Fresh

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