The domestic dog is one of the best examples of domestication by humans dating several tens of thousands of years ago. Domestication often results in a species increasing their phenotypic variation and geographical distribution. However, as dog breeds have such a high degree of phenotypic variation an insight into their origins based on shared traits is complicated. This is also true for genetic inferences as there is such a long history of trading and mixing between dogs of different geographical location and inbreeding of some lineages. Whilst some research has suggested origins in the Middle East and East Asia the oldest dog remains have been discovered in Western Europe and Siberia, dating from15, 000 to 36,000 years ago. However, it is important to note that the species of these remains is contentious. When the remains from the Middle East and East Asia were dated they were found to be older than 13,000 years old. All of this information combined still leaves a very confusing and unclear view of the origins and date of dog domestication.
This study by Thalmann et al. (2013) uses DNA extracted from the earliest dog to try and establish the origin of modern dogs. Using DNA from prehistoric dogs and modern wolves both complete and partial mitochondrial genomes were generated. By comparing these with genomes of wolves, dogs and coyotes generated a ‘well-resolved phylogeny’. I was found that dogs fall within one of four clades. Three of these account for 78% of the sequences used in the study and are sister to the more ancient canids in Europe. The final group, clade A, was the most diverse and includes the Dingo and some Chinese indigenous dogs and are most closely related to an ancient wolf sequence from Switzerland dating to ~32,100 years ago. The other three clades also have common ancestors found in various locations in Europe providing support for the hypothesis that the origin of dogs is in Europe.
Full citation: Thalmann, O., B. Shapiro, et al. (2013). “Complete Mitochondrial Genomes of Ancient Canids Suggest a European Origin of Domestic Dogs.” Science 342(6160): 871-874. Article available here.
News report about article: http://www.sci-news.com/genetics/science-dogs-domesticated-europe-mtdna-01550.html