Middle Stone Age humans in high-altitude Africa Recent archaeological research has produced evidence of the earliest human occupation of high-altitude habitats in the Andes and the Tibetan Plateau. Ossendorf et al. now present the oldest evidence of human settlement and adaptation to areas above 4000-meter elevation in Africa (see the Perspective by Aldenderfer). Their excavations at a rock shelter in the Bale Mountains of Ethiopia reveal obsidian artifacts and faunal remains, including abundant burnt bones, mostly of giant mole-rats. The findings reveal the environmental conditions and show how Late Pleistocene humans adapted to the harsh environments of these glaciated high-altitude African landscapes. Science , this issue p. 583 ; see also p. 541