Produced by: Mohsin Shaikh
Human adaptations to high altitudes are being observed in real-time on the Tibetan Plateau, where communities thrive despite oxygen levels that would cause hypoxia for most.
Living at 3,500 meters above sea level, Nepalese communities face extreme oxygen scarcity, driving biological adaptations for survival over 10,000 years.
Cynthia Beall, anthropologist at Case Western Reserve University, discovered that women with high hemoglobin oxygen saturation have greater reproductive success in high-altitude conditions.
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Women with average hemoglobin levels and high oxygen saturation avoid thickened blood, reducing heart strain while maximizing oxygen delivery to tissues.
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Nepalese women with wider left ventricles and increased blood flow into their lungs excel at pumping oxygenated blood efficiently, aiding survival in thin air.
Women with the highest rate of live births exhibit traits optimizing oxygen transport, highlighting natural selection’s role in shaping high-altitude survival.
Long marriages and early reproduction also contribute to higher birth rates, showing the interplay of cultural and biological factors in evolutionary success.
This ongoing evolution on the Tibetan Plateau underscores how environmental stressors like low oxygen continue to shape human biology in measurable ways.
These groundbreaking findings, detailed in the Proceedings of the National Academy of Sciences, deepen our understanding of human evolution under extreme conditions.