Study: Dogs Have Been Close With Humans for Around 30,000 Years

A pit bull named OJ wears sunglasses on the Embarcadero in San Francisco on March 16, 2015. Robert Galbraith/Reuters

Other than a book, a dog is man's best friend. And that's been the case since way before books were invented—perhaps as long as 30,000 or even 40,000 years ago, according to recent DNA evidence.

A new study, published Thursday in the journal Current Biology, suggests that the close interspecies bond that exists between humans and dogs may extend 27,000 or even 40,000 years back. That's a dramatic jump from 11,000 to 16,000 years ago, when dogs were previously thought to have split from their wolf ancestors.

Led by Harvard research fellow Pontus Skoglun, the authors of the study examined DNA belonging to a 35,000-year-old Siberian wolf specimen. Their genomic analysis led them to conclude that the wolf was part of a population "that diverged from the common ancestor of present-day wolves and dogs very close in time to the appearance of the domestic dog lineage," according to an abstract.

That means domesticated dogs may have been hanging out with humans during that same era, more than 20,000 years ago. The impetus for this finding was the discovery of the ancient bone, the abstract notes:

The researchers made these discoveries based on a small piece of bone picked up during an expedition to the Taimyr Peninsula in Siberia. Initially, they didn't realize the bone fragment came from a wolf at all; this was only determined using a genetic test back in the laboratory. But wolves are common on the Taimyr Peninsula, and the bone could have easily belonged to a modern-day wolf. On a hunch, the researchers decided to radiocarbon date the bone anyway. It was only then that they realized what they had: a 35,000-year-old bone from an ancient Taimyr wolf.

Another tidbit from the study: That Taimyr wolf has a lot in common, genetically speaking, with your Siberian Husky or Greenland sled dog.

But the dog won't attack you. It's been conditioned not to for 30,000 years.