Canine researchers have long believed that after the Europeans arrived in the New World, their four-legged friends ended up genetically dominating the dogs already living here. But, now a new study indicates modern breeds in the Americas largely trace their ancestry to dogs brought to the continent by native peoples of Asia.
The research appears in the Royal Society journal Proceedings B.
"Our results confirm that American dogs are a remaining part of the indigenous American culture, which underscores the importance of preserving these populations," said lead scientist Peter Savolainen of the KTH Royal Institute of Technology in Stockholm, Sweden, the BBC reported.
Savolainen and his research team compared mitochondrial DNA from Asian and European dogs, ancient archaeological samples from the Americas, and American dog breeds.
The study, which focused on Chihuahuas, Peruvian hairless dogs, and Arctic sled dogs, followed the ancestries of American pooches back to East Asian and Siberian dogs, and also found direct genetic connections between ancient American dogs and modern breeds.
Researchers explain that the ancestors of Native Americans crossed a land bridge linking northern East Asia and North America thousands of years ago. So, it would follow, if those ancient immigrants were accompanied by furry companions, there would be a genetic connection to dogs found in Asia.
The new findings, however, re-establish the notion the popular Chihuahua did in fact originate in Mexico, despite suggestions by some scientists the small-sized and often-yappy breed had roots in China.
"It was especially exciting to find that the Mexican breed, the Chihuahua, shared a DNA type uniquely with Mexican pre-Columbian samples," said Savolainen. "This gives conclusive evidence for the Mexican ancestry of the Chihuahua."
The team also examined stray dogs in America, many of which were determined to be of European lineages.
However, in Mexico and Bolivia, high percentages of stray dog populations showed indigenous canine ancestry.
The research also showed the Carolina Dog, a stray dog population in the United States, could also have a native American origin, Savolainen added.
Sometimes referenced in the U.S. South as the "yaller dog", the Carolina Dog came to the attention of scientists in the 1970s, when a senior ecologist at the University of Georgia noticed the canine's similarities to the Australian dingo.
The Carolina Dogs sampled in the latest study, though, belonged to a branch of the dog family tree specific to East Asia.