Origin of the domestic dog matched across Eurasia and its branch is phylogenetically rooted in the same sequence as the Altai dog (not a direct ancestor). The subclade d2 hybrid haplotypes are found in 2.6% of South-West Asian dogs. Haplogroup E: Derived from post-domestication wolf–dog hybridization in East Asia, (rare distribution in South-East Asia, Korea and Japan). Haplogroup F: Derived from post-domestication wolf–dog hybridization in Japan. A study of 600 dog specimens found only one dog whose sequence indicated hybridization with the extinct Japanese wolf. It is not known whether this hybridization was the result of humans selecting for phenotypic traits from local wolf populations
Dog capabilities, and physical attributes. Their long association with humans has led dogs to be uniquely attuned to human behavior and they are able to thrive on a starch-rich diet that would be inadequate for other canid species. Dogs vary widely in shape, size and colors. Dogs perform many roles for humans, such as hunting, herding, pulling loads, protection, assisting police and military, companionship and, more recently, aiding disabled people and therapeutic roles. This influence on human society has given them the sobriquet "man's best friend". In 1999, a study of mitochondrial DNA indicated that the domestic dog may have originated