Published: Mon, July 09, 2018
Medicine | By Douglas Stevenson

Native Dogs of the Americas Were Wiped Out by European Colonization

Native Dogs of the Americas Were Wiped Out by European Colonization

Using genetic information from 71 archaeological dog remains from North America and Siberia, an global team led by researchers at the University of Oxford, University of Cambridge, Queen Mary University of London, and Durham University showed that "native" (or "pre-contact") American dogs, which arrived alongside people over 10,000 years ago and dispersed throughout North and South America, possessed genetic signatures unlike dogs found anywhere else in the world.

"Archaeological evidence has long suggested that ancient dogs had a dynamic history in the Americas, but the fate of these pre-contact dogs and their relationship to modern American dog populations was largely unknown", said Angela Perri, a co-first author of the study.

In an ironic twist, the researchers also found that something of the original dogs of the Americas still exists - an infectious cancer with the genome of the dog in which it first appeared. Over thousands of years, these canines traveled all across the Americas - until the Europeans arrived.

"By looking at genomic data along with mitochondrial data, we were able to confirm that dogs came to the Americas with humans, and that almost all of that diversity was lost - most likely as a result of European colonization", coauthor Kelsey Witt, a graduate student who led the mitochondrial DNA testing, says in a press release from the University of IL.

Previous research showed that this founder was genetically similar to modern Siberian huskies, Alaskan malamutes and Arctic sledge dogs and most likely belonged to an isolated population.

Even though native or "pre-contact" dogs were quickly wiped out, their genome closely matches a kind of venereal disease that causes canine transmissible venereal tumors (CTVT). The experts received samples of dogs during the excavations held in the territory of modern IL. Europeans might have simply preferred to only breed and sustain the dogs they brought over from their homelands.

But then, sometime after the 15th century, these ancient dogs disappeared.

While dogs have been man's best friend for more than 10,000 years, a study of their remains found that early dogs likely arrived from Siberia and left a cancerous tumour that is still found in their canine descendants.

For the study, the researchers analyzed genetic information from 71 archeological canine remains from North America and Siberia.

"This suggests that this tumor originated in or near the Americas", Witt said. "Few modern dogs have any trace of these ancient lineages".

When they compared it to the genetic makeup of modern pooches, they confirmed what other scientists have long suggested: The first dogs of North America, similar to Arctic dogs like Siberian huskies or Alaskan malamutes, were brought to the continent when people crossed the land bridge that formed between Russian Federation and Canada. "The genome that it has is the genome of the very, very first" dog to get the disease. And there is some genetic legacy of those ancient North American dogs. "So in a weird way, the ancient dogs of America live on through these cancerous cells". Some ancient remains excavated decades ago and labeled wolves or coyotes might actually be from dogs or hybrids, but it will take DNA analysis to find out, she said.

"The cancer genome we found was a real surprise", Linderholm said. If that happens, she added, researchers can "work our way further back in time".

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