The dog (Canis familiaris) was the first animal to be domesticated, several thousands of years prior to the domestication of other animals. However the timing and location of domestication still remains difficult to pinpoint. Today there are thousands of different types of dogs in the world, but most of the modern breeds just trace their origin back to the last 200 years. However genome wide SNP data has shown that there are some modern breeds that appear basal compared to all others. These are breeds can mostly be found in the geographical fringes of dog distribution (for example Scandinavia), and they have been genetically isolated from other dogs for a long time.
Here we have generated a low coverage genome from an ancient dog dated to ca 2830-2485 cal BC. We sampled a tooth from a complete skeleton found in a burial in South Eastern Sweden. The dog is morphologically similar to modern dogs of the Spitz-type which include a number of basal breeds.
The genome of the ancient Swedish dog is very similar to Spitz-type dogs and other breeds that have been identified as 'basal' or 'ancient' breeds based on their genetic signature. This pattern suggests that the foundation for some dog breeds had started more than 4,600 years ago and that such basal breeds have received relatively little admixture from other dogs since then. Furthermore, we investigate whether the ancient Swedish dog received introgession from wolves, in particular from an extinct Siberian wolf linage which has admixed with modern breeds from high latitudes.
The genome from our 4,600 year old dog provides a first step towards understanding the origin of dog breeds beyond the historical records of the past 200 years which can also help to shed light on dog domestication.