Charles Darwin, the legendary naturalist and scientist known for his theory of evolution, was wrong about dogs. He thought remarkable diversity of dogs must reflect interbreeding with several types of wild dogs. But the DNA findings say differently.
Although you see a huge variety of 161 breeds today, from bulldogs, to gold retrievers and greyhound, all dogs are domesticated wolves and their ancestor is gray wolf (Canis lupus). This domestication may have happened once or twice (the number of times dogs were domesticated from wolves is still an ongoing debate based on continuing DNA discoveries from fossils).
How and when this domestication happened has still been a mystery and scientists don’t agree on the answer. It was thought until very recently that dogs were wild until about 40,000 years ago. But DNA analysis published in 1997 suggests a date of about 130,000 years ago for the transformation of wolves to dogs. This means that wolves began to adapt to human society long before humans settled down and began practicing agriculture.
This earlier timing casts doubt on the long-held myth that humans domesticated dogs to serve as guards or companions to assist them. Rather, say some experts, dogs may have exploited a niche they discovered in early human society and got humans to take them in for better chance of survival.
More theories and supporting evidence on evolution of dogs remain to be established.