Scientists have used DNA sequencing technology to examine the dog genome and gain greater insight into the evolution of man’s best friend. A new study by author Dong-Dong Wu and researchers published in the Molecular Biology and Evolution journal has studied the genetic basis of how Tibetan Mastiffs, which originally lived in the pains, adapted to the high altitudes.

The authors looked at genome-wide mutations of 32 mastiffs and compared them to 14 grey wolves and 20 Chinese native dogs. A total of 120,000 mutations were identified. These mutations are also called single nucleotide polymorphisms (SNPs). On analysis, the researchers narrowed down the SNPs to 16 genes that underwent positive selections in the mastiffs. Out of these selections, 12 were necessary for high-altitude adaption.

More specifically, the candidate genes were linked to energy production that is critical to surviving low-oxygen, high-altitude conditions. Other high-altitude animals have been found to have similar categories with selective signatures. Wu said these results suggest that “independently, genes can be adaptively evolved to yield similar phenotypic adaptive responses.

A hypoxia-inducible factor known as EPAS1 has been found in the hypoxia adaption of Tibetan people as well, indicating a possible convergent evolution between humans and dogs. However, the authors noted that more research is needed to fully compare high altitude adaption between the two species.