In the past, dogs were believed to have a single ancestor, originating from the ancient wolf species. However, recent research has challenged that notion.
Dogs have coexisted with humans since ancient times, but their origins have been debated. Recent studies indicate that dogs do not descend from just one but at least two ancient wolf species. Furthermore, this divergence co-occurred in two different regions of Asia and Europe.
Dogs first appeared approximately 15,000 years ago, long before the advent of agriculture. At that time, dogs were among the earliest animals to be domesticated as pets. They branched off from the ancient wolf species, but scientists are uncertain whether this domestication occurred in Europe or Asia.
Earlier research had concluded that dogs were only domesticated once, but their origin’s timing and exact source remained disputed. The complexity of the matter lies in the fact that archaeological evidence of dogs dates back thousands of years in both the massive Asian and European continents. The latest research indicates that dogs were domesticated at least twice in different periods and regions worldwide.
By comparing genetic samples from fossil remains discovered by archaeologists, a research team led by Oxford University demonstrated that dogs originated from two distinct wolf species (or, more precisely, an extinct ancient wolf species that is a common ancestor of modern wolves and dogs). These two ancient wolf species lived on opposite ends of Asia and Europe, one in the East and the other in the West.
This means that two different groups of humans during the Stone Age in two other regions of Asia and Europe independently came up with the idea of domesticating these four-legged friends because they found them helpful.
A crucial piece of new evidence was found in a Stone Age tomb at Newgrange in Ireland a few years ago. It contained the fossil remains of a 4,800-year-old dog, which still preserved DNA for study.
“DNA samples from the dog’s bones at Newgrange preserved the most ancient DNA that we have ever encountered, providing a remarkably well-preserved ancient genome for study,” said Dan Bradley from Trinity College Dublin. “It’s not just a postcard from the past; it’s a big gift.”
Bradley’s research group and support from researchers at the National Museum of Natural History in Paris analyzed DNA from 59 fossil dog remains dating from approximately 3,000 to 14,000 years ago. Their genetic data, including samples from Newgrange, were compared to data from 2,500 previously studied modern dog genomes.
“Reconstructing the past from modern DNA is like opening a history book to read, and you don’t know which pages are missing,” said lead researcher Laurent Frantz. “On the other hand, ancient DNA is like a time machine; it allows us to look straight into the past and see exactly what happened.”
The diagram reveals two distinct dog breeds in different geographical areas, long before dogs first appeared in Europe or East Asia. It also shows a significant change in dogs’ dominance in Europe, possibly due to dogs from East Asia migrating with their human companions and gradually replacing the indigenous European dogs.
The likely events are that the ancient wolf species split into two branches, East and West of the Asian-European continent, each being domesticated separately in different regions before going extinct. After domestication in both areas (around 6,400 years ago), dogs from the East traveled with their human companions to Europe, where they interbred and gradually replaced the indigenous European dogs.
Today, most dog breeds are hybrids between dogs from East and West. That’s why decoding the DNA of modern dogs has been so challenging for scientists. They believe that in certain dog breeds, such as the sled dogs of Greenland or Siberian huskies, there’s a distinct mix of Western Eurasian dog ancestry and East Asian dog lineage.
This new research answers numerous long-debated questions, but further investigation is necessary. The story of the origin of dogs in the Eurasian continent and their migration alongside humans to Europe from an early age is plausible. Still, more archaeological evidence is needed to solidify this argument.
To delve deeper into this matter, scientists aim to combine genetic information from ancient and modern dog species with physical analysis and archaeology to construct a more specific timeline of our four-legged friends’ appearance. Another research direction involves comparing the dingo in Australia, considered a descendant of East Asian dogs. If the dingo lacks DNA traces of its European counterparts, the hypothesis put forth by these scientists becomes even more specific.