For millennia, the massive Tibetan mastiff has laid literal claim to the label “top dog.”
For millennia, the massive Tibetan mastiff has laid literal claim to the label “top dog.”
The fierce breed, which boasts a lionesque mane and can reach 150 pounds, has long protected Himalayan flocks of sheep from Tibetan wolves and other predators lurking upward of 15,000 feet above sea level — heights no other domestic breed can survive.
Prior research suggests the Tibetan mastiff took an evolutionary shortcut by breeding with the Tibetan wolf, which had already adapted to the altitude by evolving more efficient hemoglobin: the protein that snares oxygen in the bloodstream and distributes it to organs.
The University of Nebraska–Lincoln’s Jay Storz, Tony Signore and colleagues have now determined that sleeping with the enemy granted the Tibetan mastiff a hemoglobin architecture that catches and releases oxygen about 50% more efficiently than in other dog breeds. Signore reached the conclusion after testing the Tibetan mastiff hemoglobin against that of multiple domestic breeds, including Storz’s own half-Great Pyrenees, half-Irish wolfhound.
Continue reading at University of Nebraska - Lincoln.
Image via University of Nebraska - Lincoln.
