Evidence from Tibet shows humans are still evolving silently

(Dan Tri) - As evolution continues, the human body continues to change to adapt to seemingly the harshest living environments.

Amid the harsh environment of the Tibetan plateau, where oxygen levels are only two-thirds that of the plains, indigenous communities have thrived for thousands of years.

Recent studies reveal unique adaptive mechanisms, suggesting that human evolution is still quietly ongoing.

In the high mountains of Tibet, where most tourists are susceptible to altitude sickness, indigenous communities still work, live and develop normally.

This has long posed a big question for scientists : how have their bodies adapted to thrive in an oxygen-deprived environment?

In Tibet, humans are still evolving (Photo: Getty).

According to Science Alert, people who are not used to living at high altitudes often experience reduced atmospheric pressure, leading to a sharp drop in the amount of oxygen they breathe in. This condition of the blood not transporting enough oxygen to the tissues can cause headaches, dizziness, and even pulmonary edema, which can be life-threatening.

However, Tibetans are almost immune to these dangers.

New research by anthropologist Cynthia Beall of Case Western Reserve University (USA) has shed some light on this secret. Her team followed 417 Nepalese women living at altitudes of more than 3,500m to find biomarkers reflecting the ability to adapt to low-oxygen conditions.

The key indicator chosen was the number of healthy births. According to the research team, women who are able to overcome the stress of pregnancy and childbirth are the ones with the most clearly adapted physiology, thereby passing on the advantage to the next generation.

The results showed that women who had the highest number of healthy births, an average of 5.2, had hemoglobin levels in the average range rather than being too high or too low.

However, the highlight is that the oxygen saturation of hemoglobin is very high, helping the blood transport oxygen effectively even though the amount of oxygen in the air is less than normal.

This finding is particularly significant. High hemoglobin levels can help blood carry more oxygen, but they can also thicken it and put stress on the heart. Tibetan physiology appears to have found an “optimal balance” that increases oxygen transport without compromising cardiovascular function.

Not only that, the most fertile women also showed greater blood flow through their lungs and a larger-than-average left ventricle, the chamber of the heart that pumps oxygen-rich blood throughout the body.

The combination of these characteristics helps the body increase the rate at which oxygen is transported, making the most of the limited oxygen in the thin air of high mountains.

Besides biological factors, some cultural factors such as early marriage also affect the fertility rate. However, the research team believes that physiological characteristics are the key factor determining superior adaptability.

“This is a rare example of natural selection at work. Understanding how these populations adapted helps us better understand the evolution of our own species,” Beall said.

This research not only explains the incredible endurance of Tibetans but also opens up new approaches to medicine, especially in the treatment of diseases related to lack of oxygen or cardiovascular disease.

Source: https://dantri.com.vn/khoa-hoc/bang-chung-tu-tay-tang-cho-thay-con-nguoi-van-dang-am-tham-tien-hoa-20251125071226348.htm