ABSTRACT
The immense majority of human beings have spent the very largest part of their lives outside of nature, in man-made environments. Ever since the Old Stone Age, and almost every-where on earth, it is chiefly through social mechanisms that the human species has adapted itself to an immense range of climatic and topographic conditions. Its subtropical origin is reflected in the fact that, whatever the climate or season, human beings arrange their ways of life and local environments in such a manner that their bodies are protected from extreme heat or cold. The technologies which enabled mankind to spread over the whole globe were on the whole very simple. According to modern theories, all human languages have a common origin and are based on a "universal grammar" which took its form at the same time as the human brain. As far as can be judged, only the human species has a true language.
