As animals go, dogs are remarkable due to their vast array of physical shapes, sizes and abilities. In fact, Charles Darwin remarked upon this in his ground-breaking classic, On The Origin of Species:
if, for instance, it could be shown that the greyhound, bloodhound, terrier, spaniel, and bull-dog, which we all know propagate their kind so truly, were the offspring of any single species, then such facts would have great weight in making us doubt about the immutability of the many closely allied natural species.” [p. 105]Although we do know that dogs are the domesticated descendants of wolves, we don’t know whether the wolf befriended humans just once, nor are we sure where this happened. These questions have been the subject of debate in the scientific community for many decades.
Although a number of archaeologic and genetic studies have investigated the domestication of the wolf, they provide few direct answers about the origin of dogs. For example, the first archaeologic remains that can be confidently assigned to dogs appear in Europe approximately 15,000 years ago, and in Far East Asia more than 12,500 years ago (i. e.; ref). Thus, archaeologists think that the wolf could have been domesticated more than once, even though most genetic studies indicate the opposite (ref) — but at the same time, there is conflict regarding whether this domestication event occurred in Europe, Central Asia or China. Where did dogs originate, and were they the product of only one domestication event? Advances in modern DNA sequencing methodologies now make it possible to answer these questions with greater certainty.