In its present form from the existing wolf no dog can not occur. Confirmation of this is the number of chromosomes present in the same number – 78, as in dogs and a wolf. In jackal chromosome set and another dog from him could not happen. Dog freely hybridizes only with the wolf and give fertile offspring. Apparently extinct volkoobrazny ancestor of dogs and wolves has been widely distributed around the globe, and from him there were local dogs, namely in Europe, Asia, North Africa, possibly in North America. On other continents dogs were brought later.
Dog – the first animal tamed and domesticated by man. Judging from archaeological excavations, it was in the Stone Age, when ancient people are not engaged in farming and herding, and hunted his own food and clothing for hunting wild animals. In Europe the oldest finds of bones of domestic dogs are made in the so-called "Danish cuisine" and Swedish Neolithic sites in Sehalmene. Age of their inhabitants in the 10-12 thousand years. In England the remains were found dogs, dating 7200-7900 years. BC. er. Iran has discovered the remains of dogs age approximately 11,5 thousand years.
Almost the same in antiquity (9,5-8,3 thousand years BC. Er.) Skeletal remains were found in a cave Beverhed in Idaho. V1862 in the lake dwellings Swiss lakes have been found remains of dogs related to the Neolithic period (about 10 thousand years BC. er.). They belonged to a dog of small stature, called peat (or swamp). Later, the remains of similar dogs were found during excavations near Munich, in Pomerania, in the caves of Belgium near Mainz, in Egyptian tombs, and in Russia – on the shores of Lake Ladoga, in the Vladimir province.