The people in Tibet live at a height of 13,000 feet where there is 40% less availability of oxygen as compared to the sea level. However, these people do not experience much mountain sickness.

The biologists in China have found that the reason behind it is the human evolution. It is the most recent and fastest case of evolution that has been discovered, up till now.

The study was conducted by a group of researchers at the Beijing Genomics Institute led by Xin Yi and Jian Wang.

The scientists compared the genetic makeup of Tibetans with Han Chinese, which are the mainstream ethnic group in China. They discovered that a minimum of 30 genes have changed in the Tibetans, as they acclimatized to the life of the plateau, which is situated at such a great altitude.

Researchers revealed that 3,000 years ago, the Han Chinese and Tibetans became separated. The report was published in Friday’s issue of Science. However, archaeologists are of the view that the Tibetan plateau inhabited much earlier.

When the people residing in plains visit the areas having high altitude, then their blood becomes thick as the body releases more red blood cells to compensate for the low level of oxygen.