Sherpas have a physiology that uses oxygen more efficiently than those used to the atmosphere at sea level. They owe this ability to an advantageous genetic mutation that gives them a unique metabolism. Sherpas actually have thinner blood, with less haemoglobin and a reduced capacity for oxygen

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Sherpas have a physiology that uses oxygen more efficiently than those used to the atmosphere at sea level. They owe this ability to an advantageous genetic mutation that gives them a unique metabolism. Sherpas actually have thinner blood, with less haemoglobin and a reduced capacity for oxygen