This Volume summarises the results of almost a decade of research work on high altitudes by the author. Though the main thrust of this volume draws heavily on the researches conducted under the aegis of International Biological programme in India, the results have been reviewed comprehensively in the light of contemporary situations in other parts of the world. While several references account for the general problem of human populations, living or working under the hypoxic conditions in India, this book systematically reviews the existing researches, explains the underlying features of adaptation and goes on the analyse the morphological and physiological adaptive responses. In addition the author has ventured into another field of anthropology, where dermato-glyphics has been used as a tool to study miscegenation in a high altitude living population. It is hoped that this work will stimulate wider interest in one of the most fascinating fields i.e., high altitude studies.