Scientists Discover Dogs Are Humans Oldest Companions, DNA Shows

Dogs are not only man’s best friend, it turns out they are also the oldest domesticated animal by humans. New research published in the journal Science. lead by an international team found that dog domestication can be traced back 11,000 years to the end of the last Ice Age.

This confirms that dogs were domesticated before any other known animal. An international team of scientists analyzed the whole genomes (DNA in the nuclei of biological cells) of 27 ancient dog breed remains linked to a mixture of archaeological cultures. Researchers compared these to each other and to modern dogs, and they found some stunning results.

The scientists found that dog genetic patterns directly mirror human ones because people took their animal friends with them when they migrated. But there were also some important differences, the scientists note.

According to the study, our canine partners were widespread across the northern hemisphere at this time and had already split into five different types of canine, BBC News reported.

Despite the expansion of European dogs during the colonial era, traces of these ancient indigenous breeds survive today in the Americas, Asia, Africa, and Oceania. Breeds like the Rhodesian Ridgeback in southern Africa, and the Chihuahua and Xoloitzcuintli in Mexico retain genetic traces of ancient indigenous dogs from the region.

European dogs were originally diverse, seeming to emerge from two very different populations, one related to Near Eastern dogs and another to Siberian dogs.

While the ancestry of dogs in East Asia is complex, Chinese breeds seem to derive some of their ancestries from animals like the Australian dingo and the New Guinea singing dog, with the rest originating from Europe and dogs from the Russian steppe.

But at some point, perhaps after the onset of the Bronze Age, a single dog lineage spread widely and replaced all other dog populations on the European continent. The research provides context to some of the unknowns in the natural history of our close animal companions.

Dr Pontus Skoglund, co-author of the study and group leader of the Ancient Genomics laboratory at London’s Crick Institute, told BBC News: “Dogs are really unique in being this quite strange thing if you think about it, when all people were still hunter-gatherers, they domesticate what is really a wild carnivore – wolves are pretty frightening in many parts of the world. The question of why did people do that? How did that come about? That’s what we’re ultimately interested in.”

Greger Larson, a co-author from the University of Oxford, said: “Dogs are our oldest and closest animal partner. Using DNA from ancient dogs is showing us just how far back our shared history goes and will ultimately help us understand when and where this deep relationship began.”

Dogs have always been thought to have evolved from wolves that were tamed to serve as hunting companions and guard dogs.

The results of the recent study suggest all dogs derive from a single extinct wolf population or a few different closely related ones. If there were multiple domestication events around the world, these other lineages did not contribute much DNA to later dogs, according to the study.

However, Skoglund expressed that we don’t know for sure when or where the initial domestication occurred. “Dog history has been so dynamic that you can’t really count on it still being there to readily read in their DNA. We really don’t know – that’s the fascinating thing about it.”