When humans changed their nomadic hunting lifestyle to become planters and farmers developed a more collective social organization. Domestication of farm animals for practical reasons and the integration of dogs into men's new activities, played a major role in the success of humanity. Archeological evidence of an existing canine-human relationship are numerous and date from more than 30,000 years ago. For instance, a 50-meter trail of footprints of a boy and a large canid part-wolf, part-dog lies in the Chauvet cave, in France. This finding suggests that approximately 26,000 years ago this child walked inside the cave accompanied by his pet . Moreover, fossilized remains found in different parts of Europe, including the Kesslerloch cave, as well as in different places in Asia, were the missing pieces in the puzzle that lead towards the conclusion that 14,000 years ago, domestic dogs were part of humans' entourage. Although the fossils found in the Goyet Cave, Belgium, and Southern Siberia suggest that the origin of the domestic dog dates back to more than 30,000 years, scientists think that the Ice Age could be the reason why neither the Belgian nor the Siberian domesticated lineages survived. Also, the discovery of dog burials demonstrate early pet domestication as well as the fact that humans gave dogs a special status. The oldest case of a double grave, consisting of a dog being buried next to a human, in Europe dates from about 14,000 years ago and is located in Bonn Overkassel, Germany. In America, this type of evidence dates from around 10,000 ago and was found in Danger Cave, in Utah.
Goyet dog 31,700 years ago.
Studies of Mitochondrial DNA provide genetic evidence that wolves are the ancestors of domestic dogs and suggest that current major dog populations have a common origin. In the process of evolution of wolves into dogs genetic changes have occurred. These include an overall size reduction as well as other morphological skeleton variations.