The origin and evolution of domestic dogs has been an interesting and controversial question for the scientific community. With whole genome sequences gathered for a total of 58 canids (12 grey wolves, 27 primitive dogs from Asia and Africa and a collection of 19 diverse breeds from across the world), we revealed an ancient origin of domestic dogs in Southern East Asia 33,000 years ago. After living in East Asia for thousands of years, a subset of dog ancestors started migrating to the Middle East, Africa and Europe, about 15,000 years ago, possibly through the Indian coastal areas. Interestingly, one of the Out of Asia lineages also migrated back to the east, creating a series of admixed populations with the endemic Asian lineages in Northern China before migrating to the New World.
This study opens many potential avenues for future research. Collection of additional samples from other parts of the World (especially the Indian coastal region and Northern Eurasia) should allow us to draw a more complete picture of the worldwide migration patterns, and their association with human populations. The study of the Chinese indigenous dogs has provided an unprecedented opportunity for illuminating the history of selection during dog domestication. For example, as dogs established stronger bonds with humans, possibly empowered by the origin of modern agriculture in the Middle East and China, strong selection for genes involved in metabolism and morphology/development emerged. Our study, for the first time, begins to reveal the extraordinary journey that our best friend has traveled on this planet, and a large and complex landscape upon which a cascade of positive selective sweeps occurred during the domestication of the dog.