If you’re not amazed by the diversity of dog body type and the huge number of habitats in which they can live, then you’re in the minority. Scientists, dog lovers and scientists who are dog lovers consider the domestic dog a species of considerable interest for the great number of forms that have evolved over a relatively short time. Some of the variation is obvious because it involves shape, size and color, while some of the behavioral tendencies are subtle. Even less obvious are the physiological difference between different types of dogs, including the recent discovery of adaptations to high altitude by the Tibetan Mastiff.
This breed of dog is most closely related to the Chinese native dogs, but in recent history, has been selected to live high in the mountains of Tibet at elevations of nearly 15,000 feet. The biggest challenge to life at such heights is the low level of oxygen. Even individuals who are quite fit can become out of breath just from walking at a casual pace under the low oxygen (hypoxic) conditions at high altitude. So, how do Tibetan Mastiffs thrive in Tibet? They do it in much the same way that wild animals and humans do—with genetic changes that affect hemoglobin concentration, the formation of extra blood vessels and the use and production of energy.
In a new study called “Population variation revealed high altitude adaptation of Tibetan Mastiffs”, scientists found that this breed of dogs has at least a dozen areas in their genome that represent adaptations to the high life. One of the genes that helps them survive in their high-altitude/low oxygen environment is similar to a gene present in the Tibetan people, who are also adapted to the high life. The rest of them are different than those of the people as well as differing from animals such as the yak and the Tibetan antelope that are also adapted to this environment.
Though much selection on our companion dogs has changed their behavior and appearance, there are also examples of changes that are far harder to observe such as the Tibetan Mastiff ‘s adaptations to high altitude.
