These early ancestors of today’s dogs were probably used for herding purposes once it was realized that they could be trained for this task. In appearance, they would certainly have been similar to the wolf but, as a result of selective breeding, differences in size soon became apparent. The grey wolf itself varies greatly in size across its wide range. Large individuals from Alaska may weigh 177 lb (80 kg) whereas the race that lives in the Asiatic steppes can be as small as 27 lb (12 kg).
By 9,000 years ago, in what is now the united states of America, a clear divergence in the size of the dog was already evident. Remains uncovered in the beaver head mountains of eastern-central Idaho have revealed both a dog similar in size to today’s retrievers, and a smaller version, which probably resembled a beagle.