When Europeans arrived in the Americas at the beginning of the 15th century, they also brought with them domesticated dogs. A new study has found these European dogs wiped out native dog populations that had lived with indigenous Americans for thousands of years.
The study further revealed that a transmissible cancer whose genome is close to that of the original dogs has lived on and actually spread throughout the world. The scientists used genetic information from 71 archaeological remains found in North America and Siberia, to show that the dogs that arrived to these areas over 10,000 years ago had genetic signatures unlike dogs found anywhere else in the world.
The research is being led by scholars from the University of Oxford, University of Cambridge, Queen Mary University of London, and Durham University. The ‘pre-contact’ dogs they studied were dispersed all the way across North and South America.
Pre-contact dogs died out without leaving genetic imprints on European species
Further study shows that once European dogs arrived, these ‘pre-contact’ dogs rapidly became extinct and did not leave any genetic imprint on the new European species. “It is fascinating that a population of dogs that inhabited many parts of the Americas for thousands of years, and that was an integral part of so many Native American cultures, could have disappeared so rapidly. Their near-total disappearance is likely due to the combined effects of disease, cultural persecution and biological changes starting with the arrival of Europeans,” senior lead author Dr. Laurent Frantz from Queen Mary University and the Palaeogenomics & Bio-Archaeology Research Network (Palaeo-BARN) at Oxford said.
History of dogs mirrors human history
The researchers are also fascinated by the way the massive differences in genetic material in dogs from different parts of the world reflected the differences in humans. Professor Greger Larson, Director of the Palaeo-BARN at Oxford and senior author of the study, explained:
“This study demonstrates that the history of humans is mirrored in our domestic animals. People in Europe and the Americas were genetically distinct, and so were their dogs. And just as indigenous people in the Americas were displaced by European colonists, the same is true of their dogs.”
The study confirmed that these native dogs originated from species from Siberia and not from native wolves as some theorists had imagined. It seems the pre-contact dogs came to the Americas during early human migration to the area.
While pre-contact dogs have all died out, one aspect of them does live on. The study also found an interesting link between the genomes of pre-contact dogs and the genomes of canine transmissible venereal tumors (CTVT).
The study revealed that the dog that first carried the CTVT was actually closely related to the American pre-contact dogs. So while they have become extinct, one aspect of their genome is now spread all over the world.
“It’s quite incredible to think that possibly the only survivor of a lost dog lineage is a tumor that can spread between dogs as an infection,” added Maire Ní Leathlobhair, co-first author, from the Department of Veterinary Medicine at the University of Cambridge. “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.”