European Colonization Killed America’s First Dogs, But A Contagious Cancer Survives

Ancient dogs traveled all the way from Siberia to make the Americas their new home, but the arrival of Europeans quickly marked their end.

Unfortunately, all that survived is a contagious cancer that's still killing dogs today.

The Trail Of The First American Dogs

Some have speculated that the first dogs in the Americas are domesticated North American wolves, but new research says otherwise.

The study, published in the journal Science, reveals that the first ever American canine life actually came from Siberia through the land bridge that used to connect North Asia to the Americas. These already domesticated dogs likely followed their human counterparts to this new land and all across the region.

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 study included seven nuclear and 71 mitochondrial genomes from ancient North American and Siberian dogs over 9,000 years.

"By looking at genomic data along with mitochondrial data, we were able to confirm that dogs came to the Americas with humans, and that nearly 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 Illinois.

The team found that it's likely that ancient dogs migrated from Siberia alongside humans. Over thousands of years, these canines traveled all across the Americas — until the Europeans arrived.

The Disappearance Of Ancient Dogs

Looking closely at the analysis of the genomes, the researchers discovered that the ancient dogs died out when Europeans colonized the Americas. Scientists have yet to find a definite cause for the near-total disappearance of the indigenous dogs.

"It is known how Indigenous peoples of the Americas suffered from the genocidal practices of European colonists after contact," author Ripan Malhi, an anthropology professor at the University of Illinois, explains. "What we found is that the dogs of Indigenous peoples experienced an even more devastating history and a near-total loss, possibly as a result of forced cultural changes and disease."

The reason may not be certain, but the sudden absence is palpable. Only a few modern dogs even have traces of the ancient lineage.

Cancer Survived From Extinction

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.

However, the organism that was found to be the most closely related to the vanished lineage of American dogs is Canine transmissible venereal tumor or CTVT, which is a contagious type of cancer afflicting dogs.

The origins of CTVT go 8,000 years ago, first from the genitals of a canine and then evolving into a parasite that can be transmitted sexually. It spread all over the world, a tumor that modern dogs still can catch.

Impressively, the cancer still has the primogenitor's genes, which researchers discovered likely originated from Asia and then got to America through the first dogs that migrated a couple of millennia ago.