Nature Knows 07 - Evolution Miracle In Tibet

Human settlement in the Tibetan Plateau dates back ten thousand years ago when fresh migrants pushed the earlier settlers up the Himalayas. Those who live in the plains find the rarified air in the Plateau with less Oxygen difficult to breathe in and may experience severe hypoxia. Scientists and researchers have found that the settlers in the Plateau have evolved features that maximise oxygen delivery, albeit by the process of natural selection. The researchers confirmed that the traits stand the test of evolutionary fitness, one of the markers is reproductive success, they are passed on to the next generation. A measurable trait is higher number of live deliveries per women; though haemoglobin level in their blood was average, but oxygen saturation of haemoglobin, high. these adaptations maximize oxygen delivery to cells and tissues that ensures child health, without thickening the blood avoiding stress on the heart for pumping high-viscosity blood. This evolution in homo sapiens is nothing short of a miracle.