With most changes to the physical aspects of people living in a certain region, it takes hundreds to thousands of years to notice these changes. However, recently scientists have discovered that we might have a rare example of human evolution in our time. A study shows that Tebitans are actively evolving to survive high altitudes. Curious as how they’re doing it? Then keep reading to discover more.
How Natural Selection Shapes Physiology of Tibetans
Tibetans live on the Tibetan Plateau, which is one of the highest regions on Earth with an average elevation of 4500m above sea level. Living here presents a unique survival challenge: the high altitude reduces the amount of oxygen in the air. Unlike people who live at sea level, Tibetans have evolved distinct biological traits that help them thrive in this extreme environment. A study of 417 Nepalese Tibetan women found that those with the highest reproductive success shared specific oxygen transport adaptations: moderate hemoglobin levels, high oxygen saturation, and strong heart function.
These adaptations allow Tibetans to efficiently deliver oxygen throughout their bodies without the negative effects of excessive red blood cell production. In most people, low oxygen triggers a rise in hemoglobin, which can thicken the blood and strain the heart. Tibetans, however, have developed a more balanced system, ensuring survival in low oxygen environments without increased cardiovascular risk.
Evolution in Action at High Altitudes
Scientists consider this a rare example of human evolution in real time. While cultural factors, such as diet and lifestyle, may contribute to survival, biology remains the key driver. These oxygen-processing traits are passed down through generations, ensuring that Tibetans continue to adapt to their high-altitude homeland.
This research highlights how natural selection still actively shapes human populations. Understanding these genetic adaptations not only provides insight into human evolution but could also inform medical advancements for people suffering from oxygen-related illnesses.
Credit:
- PNAS: Study
- Feature photo credit: Eugene Nelmin/Unsplash
