Sometime prior to 15,000 years ago, a group of sort of friendly wolves began to interact with a group of somewhat tolerant human populations, and from the initially shaky alliance, the first pets developed.

But according to new research, cited on csmonitor.com, the process may have occurred in more than one area of the world, based on fossil evidence and new DNA investigations.

Greger Larson, principal investigator at the Wellcome Trust Palaeogenomics & Bio-Archaeology Research Network at Oxford University, says their research indicates one set of wolf ancestors in eastern Eurasia, and a different set in western Eurasia, appear to have become domesticated around the same time, but totally independent of each other.

The team is basing their conclusion on something they uncovered during an analysis of DNA from ancient and modern dogs.  Their investigation revealed dogs from eastern Eurasia split with dogs from western Eurasia, sometime between 14,000 and 6,000 years ago.

Following the DNA trail, it appears there was a bottleneck, defined as a point associated with a significant population decline, in the genetics of the western Eurasia dogs.  They likened this bottleneck to the one in the human genome that was associated with the migration from Africa.

That evidence seemed to prove that the original thought of one source of dogs’ domestication was correct, but the researchers said some thing didn’t quite fit into the program.  That being, the discovery of dog fossils in Europe that date to before the bottleneck occurred, about 15,000 years ago.

The ancient dog was mostly similar to today’s European dogs, but there was also a relic in the genetics that puzzled the team.

Larson said, “We’re guessing this is from the original European population that was there before the east Asian dogs arrived. ”  If that is correct, it would suggest the Asian dogs almost completely replaced the European dogs.

Not everyone agrees, and some suggest the genetic relic is a leftover from the wolves and not the domesticated dogs.  Even Larson admits the paper, published in the journal Science, is not “the smoking gun.”

“This paper is a hypothesis based upon a series of bits of evidence that we’ve strung together to make what we think is a really plausible argument,” continued Larson.  “We think it’s more likely there were two rather than one domestication episode. But, what’s nice about this is it gives a framework to interpret all future data.”