Published: Mon, July 09, 2018
Medical | By Johnnie Horton

Dogs arrived from Siberia, left cancerous tumour behind

Dogs arrived from Siberia, left cancerous tumour behind

Lead archaeologist Dr Angela Perri from Durham University, co-first author on the study, added: "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".

"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", Kelsey Witt, who led the mitochondrial DNA genome research as a graduate student at the University of IL, said in a news release. What we uncovered were the last traces of ancient American dogs. Although there is intriguing evidence that during this time these dogs interbred with wild canids endemic in North America, like coyotes and grey wolves. The findings "put a nail in the coffin really for [that] idea,"Perri told Live Science".

The research suggests that modern "North American" dogs, such as the Chihuahua, are actually mainly descended from Eurasian breeds introduced to the Americas after the 15th century. Still, it does look like they are mostly European in origin.

Researchers comparing the genomes of ancient and modern American dogs confirm that the first domesticated dogs of North America arrived with people over the Bering land bridge.

Scientists believe the dogs might have contracted this form of cancer much before Europeans set foot here, going as back as 8,000 years. Bizarrely, their nearly total disappearance means that the closest living relative of these bygone dogs is now CTVT, an opportunistic, sexually-transmitted dog cancer that has hitchhiked around the world at least two times over.

The dogs' ancestors who lived in the Americas most likely descended from Siberia, as per a new genetic study. These remains were sourced in the Americas, revealing that a rapid decline in the indigenous dog population took place following the arrival of settlers. The Atlantic's Ed Yong writes that these dogs were the first to be bred for a specific objective, namely pulling their humans' sleds. "We suspect that a lot of the reasons [ancient] dogs were wiped out, were similar reasons that Native American populations were destroyed", Perri said.

Anne Frank’s family tried to escape to U.S. , hit roadblocks
Even apart from losing the papers, the AP reports that immigrating to the US would have still been hard . She was eventually discovered and she died in a concentration camp in 1945, when she was 15.

"If there were millions and millions of dogs all over this continent, and a small number of European dogs came in, there would have been plenty of time for them to do what dogs do, which is mate with each other and leave their DNA behind", Karlsson said. They could also be killed purposely by the Europeans like what they did with the indigenous people. Just five of the modern samples contained even a hint of ancient dog - at most 4 percent.

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

The team also discovered a link between the pre-contact dogs and the canine transmissible venereal tumor or CTVT. It's not known when the dogs first arrived.

According to the Atlantic, the researchers found very faint hints of the indigenous DNA in some of the modern Arctic canines such as Alaskan huskies, Alaskan malamutes, and Greenland dogs.

Scientists seem to have gained some insight into the age old mystery of how ancient American dogs vanished mysteriously from the face of the earth, and it is not at all like how you would expect.

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