Pathogenesis: A History of the World in Eight Plagues

by Jonathan Kennedy

Tibetans carry a Denisovan gene mutation that affects red blood cells, making it possible to live comfortably on a 13,000-feet- or 4,000-meter-high plateau where the air contains 40 percent less oxygen than at sea level.[67] Another gene variant that increases the size of the spleen is carried by the Sama-Bajau, nomadic people who live on flotillas of houseboats in the seas off the Philippines, Malaysia and Indonesia.[68] The spleen stores oxygen-carrying red blood cells, and when humans hold their breath it expels these cells to boost oxygen levels; this helps to explain how Sama-Bajau are able to dive to depths of over 230 feet or 70 meters with nothing more than a set of weights and a pair of wooden goggles. The Inuit of northern Canada and parts of Greenland and Alaska have retained Denisovan genes that influence the storage of fats, which helps them to thrive in an exceptionally cold climate.