By a 70% to 20% margin, Americans describe themselves as “dog persons” rather than “cat persons,” and why shouldn’t they? Science has found that dog owners are less likely to be depressed than non-pet owners, that dog owners have a lower rate and blood pressure, and that dog owners get plenty of exercise.
Obviously, things weren’t always this way, though. Dogs weren’t always the domesticated companions of humanity. However, it turns out that canines have been man’s best friend for a lot longer than most might have thought.
Researchers have discovered the bone of an ancient wolf, whose DNA suggests that dogs diverged from wolves between a staggering 27,000 to 40,000 years ago, not the previously believed range of 11,000 to 16,000 years ago.
In this latest study, which was published in the journal Current Biology, researchers carbon-dated a Taimyr wolf bone found in Siberia. They concluded the bone to be about 35,000 years old, and pointed to the wolf as possibly being the most recent common relative of modern wolves and dogs.
In other words, dogs and wolves apparently split from their common ancestor at least 27,000 years ago.
“Although separation isn’t the same as domestication, this opens up the possibility that domestication occurred much earlier than we thought before,” said Pontus Skoglund, the lead study author who studies ancient DNA at the Broad Institute in Massachusetts and Harvard Medical School.
The domestication of dogs is the simplest scenario explaining this new divergence, but it’s not the only one.
“The only other explanation is that there was a major divergence between two wolf populations at that time, and one of these populations subsequently gave rise to all modern wolves,” Love Dalén of the Swedish Museum of Natural History said in a release.
Under this second theory, the second wolf population would have had to have gone extinct.
“It is [still] possible that a population of wolves remained relatively untamed but tracked human groups to a large degree, for a long time,” wrote Skoglund.
The most interesting implication of this new study, however, is a re-thinking of how dogs became a part of human society — of how the treasured bond between humanity and its best friend came to be. The prevailing theory is that dogs became domestic creatures once humans started settling down and forming agrarian societies. However, if dogs began appearing some 27,000 years ago, then it’s possible that hunter-gatherers, who led a fairly nomadic lifestyle, began catching wolf cubs and domesticating them. In that case, the animals might have helped ancient humans hunt, or keep other predators away.
Whatever the case may be, dogs really are humanity’s best friend, have been for thousands of years, and will probably continue to be for millions more.