1480 one of the principal aspects of the In-ternational Biological Program. Inter-nationally about 50 nations are participating in theHuman Adaptability Proj-ect studies of adaptation of many different peoples toa wide variety of environments. Of the integrated research programs constituting the US contribution to the International Biological Program, five studies form the Human Adaptability group while eight constitute the environmental management group (1). The former consist of (i) the" International Study of Circumpolar Peoples Including Eskimos" in-volving adaptations to cold;(ii) the" Population Genetics of the American Indian" emphasizing adaptations to life under primitive conditions on the tributaries of the Amazon and Orinoco rivers;(iii) the" Biology of Human Populations at High Altitudes" in the Andes of Peru and in the Rockies but coordinated with studies in the Ethiopian highlands, and in the Himalayan and Tien Shan mountains;(iv)" Nutritional Adaptation to the Environment"; and (v) the" Ecology of Migrant Peoples." A sixth program in chrono-biology is being prepared.