the extremities and aids the release of oxygen to tissues. Modern Tibetans formed from Ancient Tibetan Highlanders (also known as "East Asian Highlanders") native to the Tibetan Plateau and a region up to the southern Altai Mountains, and from East Asian lowland farmers expanding from the Yellow River. Although "East Asian Highlanders" (associated with haplogroup D1) are closely related to East Asian lowland farmers (associated with haplogroup O), they form a divergent sister branch to them. A 2019 study by Wang et al., published in the journal Nature, similarly concluded that modern Tibetans (and closely related Tibeto-Burmese) formed from "East Asian Highlanders" and agriculturalists from the Yellow river. They further found evidence for geneflow from this ancient "East Asian Highlanders" into some populations in Southeast Asia and Japan. By comparing Tibetans to modern worldwide populations it was found that Tibetans are very closely related to other East Asians, especially Chinese and Japanese respectively. Geneflow from Tibetan-like ancestry into West Asia and Northeastern Africa was also found, however this may be caused by relative small sample size from these regions. Mythology According to Tibetan mythology, the origins of Tibetans are said to be rooted in the marriage of the monkey Pha Trelgen Changchup Sempa and rock ogress Ma Drag Sinmo. Religion Most Tibetans generally observe Tibetan Buddhism or a collection of native traditions known as Bön (also absorbed into mainstream Tibetan Buddhism). There is a minority Tibetan Muslim population. There is also a small Tibetan Christian population in the eastern Tibet and northwestern Yunnan of China. Also there are some Tibetan Hindus who mainly live in China, India and Nepal. According to legend, the 28th king of Tibet, Thothori Nyantsen, dreamed of a sacred treasure falling from heaven, which contained a Buddhist sutra, mantras, and religious objects. However, because the Tibetan script had not been invented, the text could not be translated in writing and no one initially knew what was written in it. Buddhism did not take root in Tibet until the reign of Songtsän Gampo, who married two Buddhist princesses, Bhrikuti of Nepal and Wencheng of China. It then gained popularity when Padmasambhāva visited Tibet at the invitation of the 38th Tibetan king, Trisong Deutson. Today, one can see Tibetans placing Mani stones prominently in public places. Tibetan lamas, both Buddhist and Bön, play a major role in the lives of the Tibetan people, conducting religious ceremonies and taking