Domestic dogs are good friends of humans. Although they are very different, they have a common ancestor-the gray wolf. Gray wolves are widely distributed around the world, but domestic dogs everywhere have not evolved from gray wolves everywhere. NA. Starting from comparing the genetic diversity of domestic dog populations from different regions, the researchers found that domestic dog populations from southern East Asia have the highest diversity. At the same time, the structure of the phylogenetic tree also supports the commonness of domestic dogs. On the phylogenetic tree, the end of each branch represents a group, and the more closely related groups will also be closer to the tree. Domestic dog samples from southern East Asia are all located in the phylogenetic tree. Position of the base. The text is intended to explain:. ['Domestic dogs originate from gray wolves, which have a very wide distribution worldwide.', 'Domestic dogs with different temperaments and shapes have a common origin.', 'Phylogenetic tree principle provides support for animal evolution research.', 'Research on D. genome D. NA. Fundamentally solves the problem of domestic dog origin.']