Perhaps man brought wolf cubs into the family to raise, and eventually began to take advantage of the wolf's ability to hunt and to guard the campsite. Down the millennia, through preference for wolves of certain physical and behavioral characteristics and through genetic mutation, Canis lupus changed shape, size, and color to become the wolf subspecies now known as Canis lupus familiaris. Physical traits Dogs and wolves have much in common. These are double-coated dogs with plush undercoats for warmth and coarse outer coats for protection against wind, rain, and snow. They also tend to have broad heads with plenty of brain space, but their brain capacity, muzzle-length, and strength of jaw are less than that of their progenitors.
Males mature at age three or later.
Dogs that developed from wolves in temperate or more southern climates tend to have shorter coats and be more streamlined than their northern cousins. Mastiff-type dogs probably were developed as a result of gigantism originating in populations of a mountain wolf in northern India or Tibet. Most other breeds are presumed to have developed from crosses between the northern, dingo-pariah, and mastiff groups, some with an admixture of dwarfism genes. It is in behavior that the modern dog is said to most resemble his ancient ancestor. Behaviorists and trainers exhort dog owners to learn pack theory, to establish the alpha position in the man-dog relationship, and to mimic the wolf in administering discipline.