Thousands of years ago, American dogs mysteriously vanished
09 Juillet, 2018, 15:25 | Auteur: Yves Courtet
A new study out this week in Science seems to better illuminate one of these detours.
These dogs persisted for thousands of years in the Americas, but nearly completely vanished after European contact, the researchers found.
Dozens of researchers collaborated for the expansive study.
Scientists sequenced the genomes of ancient dogs using both mitochondrial DNA genes inherited from both parents, and mitochondrial DNA, genes passed from mothers to their offspring. Namely, that the first dogs came to the Americas more than 10,000 years ago, across the Bering land bridge, or Beringia, that connected North America and Asia.
Linderholm, who directs the BIG (bioarchaeology and genomics lab) at Texas A&M and who did much of the genome work, said, "The sudden disappearance of dogs in America was probably associated with European colonization, but we don't know the details yet".
The oldest evidence for dogs in the Western Hemisphere dates back about 10,000 years, some 6,500 years after the first humans arrived.
The new study dispelled a previous theory about the origin of dogs in the Americas, which posited that they evolved from domesticated wolves. Evidence that these dogs were used in sledding, along with suggestions that they were used for hunting and hauling, means that they could have facilitated the early settlement of the Americas.
A new study sheds light on the history of dogs and their role in human life, though many mysteries remain. Instead, they realized that the native dogs had virtually vanished.
It appears that native dog populations could have been wiped out through a number of causes, including disease, persecution and Europeans' desire to raise their own breeds.
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While some American dogs might have been wiped out by epidemics or purposefully killed by Europeans, as indigenous people often were, there are likely other reasons for their demise. Did they intermix with dogs brought by European settlers? Pre-contact dogs were present as the first travellers journeyed from Siberia into the Americas and began to thrive.
In a paper published Thursday in Science, an worldwide team of archaeologists and geneticists report that.
"The picture is not as clear as they want it to be", Peter Savolainen, an associate professor in Evolutionary Genetics at the Royal Institute of Technology in Stockholm, told Gizmodo.
The researchers analyzed genetic material from 71 "pre-contact" dogs, whose remains spanned 9,000 years, and compared it with the DNA of 145 modern dogs.
Dog DNA taken from other ancient sites in the Americas not included in the study has also been found to have more similarities with the chihuahua and other South American breeds than this study did.
"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", senior lead author Laurent Frantz, a lecturer at Queen Mary University and co-investigator at the University of Oxford, said. But its DNA contains no trace of ancient dog DNA.
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