Study Provides Indices on the Fate of the First North American Dogs

by EMILIANO RODRIGUEZ MEGA, Associated Press

NEW YORK (AP) – A new study provides new evidence that the first dogs of North America have almost disappeared after the arrival of Europeans.

The only surviving legacy seems to be a cancer that was born from the cells of a dog that lived more than 8,000 years ago and that has since spread to other canines to around the world, reported Thursday an international team in the journal Science

dogs. The results confirm that the first domestic dogs from North America arrived with Asian people on the same Bering land bridge used much earlier by humans. These dogs have flourished for thousands of years, but most have disappeared after contact with Europeans. Scientists do not know why they disappeared.

"I find this really surprising," says geneticist Elinor Karlsson of the University of Mbadachusetts Medical School in Worcester, who did not participate in the study. "There were millions and millions of dogs all over the continent (which) have become extinct after the arrival of Europeans and the fact that we do not know anything about it is a big hole."

In historical gaps, researchers sequenced the genetic material of 71 remains of dogs taken from bones found in Siberia, the United States and Mexico.

They confirmed what other scientists have suggested for a long time. : The first dogs of North America, similar to Arctic dogs like Siberian huskies or Malamutes of Alaska, were brought to the mainland when people crossed the land bridge that formed between Russia and Canada. We do not know when the dogs arrived.

For Elaine Ostrander, an expert in canine genetics at the National Institutes of Health in Bethesda, Maryland, this discovery reveals something about our own behavior

their dogs, "said Ostrander, who was not part of of the study. "This study reinforces this idea and brings it back almost to the beginning of the dogdom."

Researchers have found no trace of old dog DNA in modern South American village dogs or pre-Columbian breeds like the xoloitzcuintli, the Naked Dog of Mexico. According to the study, less than 4% of the genome of modern American dogs goes back to those who lived before the arrival of Europeans.

Native dogs seem to have left a genetic legacy: a rare dog cancer known as the Transmissible Canine Venereal Tumor, or CTVT, which affected a single dog several thousand years ago.

"This is the remnant remaining the closest to this line of lost dogs," co-author Elizabeth Murchison, a geneticist at the University of Cambridge in the United Kingdom,

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