Swedish researchers say that dogs may have been domesticated much earlier than some other studies suggest.
A genetic study indicates that dogs may have begun to split form wolves 27,000 years ago.
The discovery, in Current Biology, challenges the view that that dogs were domesticated much more recently, around 15,000 years ago as humans changed from being hunter gatherers to farmers.
The study might also explain the deep bond between dogs and humans.
Other researchers had proposed that the domestication of dogs arose with the emergence of agriculture, when human hunter gatherers settled and formed communities.
The new study, which was led by Dr Love Dalen of the Swedish Museum of Natural History in Stockholm, challenges this view.
The transformation from wolf to dog may have been a slow one starting with subtle changes in behaviour.
“One scenario is that wolves started following humans around and domesticated themselves,” he told BBC News.
“Another is that early humans simply caught wolf cubs and kept them as pets and this gradually led to these wild wolves being domesticated. If this model is correct then dogs were domesticated by hunter gatherers that led a fairly nomadic lifestyle.”
Peter Smith, chief executive of the Wildwood Trust in Kent and a former conservation biologist, says that this might have been the start of the relationship between dogs and humans that has developed and become closer over thousands of years.
“(The study) is showing that the deep, deep connection has existed between man and wolves – now our dogs – for many tens of thousands of years and that is why we love dogs so much. They are part of our own evolution into a modern society,” he told BBC News.
The DNA was analysed from a small wolf bone found by Dr Dalen on the Taimyr Peninsula in northern Siberia which was radiocarbon dated to be 35,000 years old.
Another interesting finding from the Swedish study is that it also shows that the modern day dogs most closely related to the ancient Taimyr are the Siberian Husky and Greenland sledge dog, according to Dr Pontus Skoglund of Harvard Medical School, who also worked on the study.
“Our study provides direct evidence that a Siberian Husky you see walking down the street shares ancestry with a wolf that roamed northern Siberia 35,000 years ago.”