Do Dogs Originate from Wolves?

When you look at your naturally goofy and adorable dog, have you ever thought that it might once have been a wolf, a bloodthirsty creature with long, sharp teeth? Scientists have long been curious about the origin of dogs. Various theories have emerged, and recently, some have proposed the view that dogs very likely originated from wolves!

Researchers from the United States and Europe analyzed mitochondrial DNA (deoxyribonucleic acid) from 10 wolf fossils and 8 dog fossils dating from 1,000 to 36,000 years ago. Most of these fossils came from Europe; the rest were from the United States and Argentina. Comparing these fossils with 77 modern dogs, 49 gray wolves, and 4 jungle wolves, they found that modern dogs' genetic sequences most closely match those of ancient European wolves and dogs, while they are more distantly related to wolves living outside Europe or in present-day Europe.

Researchers therefore concluded that dogs' ancestors may have been wolves that once lived in Europe but are now extinct. Robert Wayne, project leader and professor at the University of California, Los Angeles, said: “The oldest domesticated dogs come from Europe, which is an inevitable conclusion.”

Due to the long history, even the bearded Darwin found the question of the origin of dogs confusing. Given the abundance of breeds, Darwin and other predecessors believed that dogs did not originate from a single species but should have a polyphyletic origin. Of course, this view faced strong challenges because people discovered some universal characteristics present in almost all dog breeds—for example, the curled and outwardly rolled tail unique among canids—which seems to suggest that dogs share a common ancestor, domesticated in one place and then spread worldwide. So now the question is, who exactly did this? And how many years ago were dogs domesticated?

Nowadays, molecular biology provides more and more evidence. Scientists trace origins mainly through mitochondrial DNA and Y chromosome DNA. The former is maternally inherited, meaning it can only be passed from mother to offspring; in other words, we can trace maternal origins through mitochondrial DNA; Y chromosome-specific DNA sequences (which are different from X chromosome sequences) are paternally inherited, passed only from father to son and can act like a surname marker. The same techniques can also be used to trace dog origins. The view that dogs mainly originated from wolves has thus received recognition.

Not talking about genes, just from an appearance point of view, dogs are very similar to wolves. For example, the sled dog Siberian Husky (detailed introduction), is sometimes actually mistaken for a wolf.