http://www.newscientist.com/article/dn27577-ancient-dna-suggests-dogs-split-from-wolves-40000-years-ago.html#.VV5M4UY_zCI
Man's best friend may be a very old friend indeed. An analysis of a bone from a newly identified ancient wolf species suggests dogs may have split from wolves as early as 40,000 years ago – with or without being domesticated at the same time. Exactly when dogs started to be domesticated and split from wolves is a matter of some controversy. Archaeological evidence analysing the shapes of canid skulls found near early human camps suggested it might have happened as far back as 35,000 years ago. DNA analysis, focusing on differences between living dog and wolf genomes, seemed to suggest they must have split much more recently – between 11,000 and 16,000 years ago.
Now Love Dalén from the Swedish Museum of Natural History in Stockholm and colleagues have sequenced the genome of a wolf that lived 35,000 years ago in Taimyr, northern Russia, according to carbon dating. This allowed them to recalibrate the molecular clock – the rate at which genetic differences accumulate over time – and better reconstruct the wolf-dog evolutionary tree. They found that dogs and wolves must have split into two separate lineages 27,000 to 40,000 years ago, bringing the DNA and archaeological evidence into line with each other.
They also found that some northern latitude dog breeds, having split from wolves, then interbred with the now extinct Taimyr wolf, which could have helped them adapt to the challenging northern environment. These breeds include the husky, Greenland sledge dog and, to a lesser extent, the Chinese shar pei and Finnish spitz.