Tibetan mastiff posing on a pedestal beside Yamdrok Lake in Tibet, China.
For centuries, Tibetan Mastiffs have been renowned for their ability to cope with high altitudes, living as they do in the mountains of Tibet, where elevations can reach close to 15,000 feet, or almost three miles, above sea level.
As every Mount Everest climber discovers – sometimes, fatally – the oxygen levels at such stratospheric heights are quite low, often leading to hypoxia, or a deprivation of oxygen to the body and its organs. But the Tibetan people and their dogs have adapted genetically to the challenges of surviving in such oxygen-scarce environs. Now, thanks to genetic sequencing, we now understand just how that evolution happened – and, it turns out, Tibetan Mastiffs have some ancient wolf ancestors to thank for it.
In a 2014 study published in Molecular Biology and Evolution, evolutionary biologists compared the DNA of 32 Tibetan Mastiff with that of 14 gray wolves and 20 Chinese native dogs, the plains dwellers from which the Tibetan Mastiff evolved. The researchers identified a dozen areas in the Tibetan Mastiff genome that helped the dogs adapt to their oxygen-poor environment by modifying such biological functions as hemoglobin concentration, the formation of extra blood vessels, and food metabolization.