New Scientist A team led by Peter Savolainen at the Royal Institute of Technology in Stockholm analysed samples of mitochondrial DNA from dogs in Asia, Africa, Europe and arctic America.
The analysis showed that modern dogs fall into five distinct genetic groups, with three of the groups accounting for more than 95 per cent of the dogs sampled. Each group is thought to be descended from a single female wolf.
But these groups do not correspond in any way to modern dog breeds, which were developed over the past 500 years. "You see the same sequence in the poodle and the German shepherd," Savolainen told New Scientist.
The greatest differences in the DNA sequences were in samples from east Asia, indicating that dogs originated in this region.