All dogs have descended from wolves or other wild canids and many still maintain their primitive looks and temperaments today.
Although this breed looks nothing similar to wolves and other wild canids, the Shih Tzu is genetically one of the domestic breeds most closely related to wolves. It is thought that this companion breed originated in China around 800 BC. The Shih Tzu is an old bread.
They may not look like it, but the modest shih tzu is more closely related to wolves than many fiercer-looking breeds. In 2004, researchers at the Fred Hutchinson Cancer Research Center in Seattle tested the genetic data of 414 dogs from 85 different breeds. They concluded that Asian breeds, from the imposing Akita all the way down to the diminutive Pekingese, are some of the oldest and most closely related to Canis lupus familiaris's wolf ancestors. Only the Nordic breeds have these dogs beat: The Siberian husky, Alaskan malamute, and Samoyed, among others, are the "best living representative[s] of the ancestral dog gene pool," the researchers wrote.
Nobody knows exactly how old the Shih Tzu is, although it existed at least as far back as 624 CE (we know this because of its presence in art from the era). As with most ancient breeds, it’s difficult to determine when and how exactly it originated, though experts have some ideas. According to one popular theory, the breed was started in Tibet by Buddhist monks and eventually made its way to China.
Although it’s been centuries since dogs became domesticated, recent DNA studies have brought to light which of the recognized breeds are the most closely related to wolves and their ancestors. The study included 414 dogs from 85 different breeds and the results might surprise you! You can read more about the study at National Geographic.