How long has Fido been "man's best friend?" A lot longer than we ever knew.
In fact, new research on a 35,000-year-old wolf bone fragment suggests that dogs and modern wolves split from their common ancestor at least 27,000 years ago and possibly as far back as 40,000 years ago.
"Previous studies have estimated that this common ancestor lived about 10-15,000 years ago," Dr. Love Dalén, a geneticist at the Swedish Museum of Natural History and a member of the team that analyzed the old bone, says in a new YouTube video (above) describing the research. "But we can now show that ... this wolf belonged to the population that was the last known common ancestor between wolves and dogs."
The five-centimeter bone was discovered in Russia's Taymyr Peninsula in 2010. The research team recently dated the age of the bone and sequenced its genome, analyzing the specimen's nuclear and mitochondrial DNA and comparing it to those of modern gray wolves and dogs, Science magazine reported.
Based on the age of the bone and its number of genetic mutations, the researchers determined that mutations in the genome appeared at a much slower rate than expected, Live Science reported. And a slower occurrence of mutations suggests there must have been a longer timescale for when modern-day wolves and dogs emerged in the family tree.
"Although separation isn't the same as domestication, this opens up the possibility that domestication occurred much earlier than we thought before," Dr. Pontus Skoglund, the Harvard Medical School geneticist who led the research, told Live Science.
What do other scientists think of the study? Some are calling for more research to determine what the findings mean for domestication.
"The present study does not rule out the possibility of a very early date indeed, but it does not rule the possibility of a much later date either," Dr. Laurent Frantz, an evolutionary biologist at the University of Oxford, who was not involved in the new research, told New Scientist. "We do not yet know whether it infers an early divergence between two wolf populations or between wolves and dogs."
The study was published online in the journal Current Biology on May 21, 2015.
How did the domestication of dogs change the course of human history? Check out the "Talk Nerdy To Me" video below.