The oldest record ever of a yak being domesticated by humans has been found in Bangga, a settlement in the Shannan prefecture of the Tibetan Autonomous Region in China. Shannan borders Bhutan and Arunachal Pradesh and the Brahmaputra river passes through it, according to a new study.
What is more, the humans in Bangga located on the Yarlung-Tsangpo (as the Brahmaputra is known in Tibet) also domesticated cattle (cows) of the taurine variety, along with yaks some 2,500 years ago.
Most modern cattle breeds of Europe as well as the temperate regions of Asia are taurine. They are distinct from the Zebu or humped breeds native to the Indian subcontinent and tropical Asia.
The study’s authors found that the residents of Bangga also produced hybrids by crossing yaks and cattle. Yaks, domestic cattle and the aurochs (ancient ancestor of cattle) are grouped by taxonomists under the genus Bos.
The international team of researchers that includes archaeologists at Washington University in St. Louis, US, zeroed in on Bangga as it is known to be rich in animal fossils.
Bangga is located at an elevation of approximately 3,750 metres (12,300 feet) above sea level. It is one of the earliest agro-pastoral settlements in the southern Tibetan Plateau and the only site in the region with abundant animal remains to have been systematically excavated in recent decades, according to a statement by Washington University.
Shannan, the prefecture in the Tibetan Autonomous Region of China where Bangga is located, borders western Arunachal Pradesh. It means Bangga is not very far from Tawang.
The researchers sifted through more than 10,000 pieces of mammal bones collected at Bangga. They identified and sorted out 193 specimens belonging to the genus Bos.
They then selected five well-preserved bones from these Bos samples to sequence for whole-genomic ancestry, according to the statement.
“Genetic analysis revealed that only one of the ancient bones came from a yak, a male individual, while the other four bones were from female taurine cattle,” according to the statement.
The researchers also expressed surprise at the presence of taurine cattle in an area so near to the Indian subcontinent, where Zebus are predominant.
Taurine cattle probably reached central and eastern Tibet from Anatolia (modern-day Turkiye) via the Silk Route and northern Tibet, the statement added.
Today, there are an estimated 14 million to 15 million domestic yaks in the highlands of Asia alone. They are also found in the Indian Himalayan Border States and Union territories such as Ladakh, Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh.
Wild yaks, never domesticated by humans, are on the brink. They are now listed as “vulnerable” by the International Union for Conservation of Nature, with only an estimated 7,500 to 10,000 mature individuals left in the wild.
Communities across the Himalayas and Tibetan Plateau also use Dzo (Male hybrid) and Dzomo (Female hybrid), bred by crossing cattle and yaks.
Evidence for early domestic yak, taurine cattle, and their hybrids on the Tibetan Plateau was published in Science Advances on December 13, 2023.