Dogs may have been domesticated much earlier than thought, finds an interesting study, adding that their special relationship to humans may go back 27,000 to 40,000 years.

This debunks earlier genome-based estimates that suggested that the ancestors of modern-day dogs diverged from wolves no more than 16,000 years ago after the last Ice Age.

The genome from the wolf from Taimyr Peninsula in Siberia, which has been radiocarbon dated to 35,000 years ago, represents the most recent common ancestor of modern wolves and dogs.

"Dogs may have been domesticated much earlier than is generally believed," said Love Dalen from the Swedish Museum of Natural History.

The DNA evidence also shows that modern-day Siberian dogs share an unusually large number of genes with the ancient Taimyr wolf.

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 did not realise 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 realised what they had - a 35,000-year-old bone from an ancient Taimyr wolf.

"The power of DNA can provide 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," added Pontus Skoglund of the Harvard Medical School and the Broad Institute.

To put that in perspective, "this wolf lived just a few thousand years after Neandertals disappeared from Europe and modern humans started populating Europe and Asia. The paper has been reported in the Cell Press journal Current Biology.