Two hundred million years ago the earth consisted of a single vast continent, Pangea, surrounded by a great planetary sea. Continental drift tore apart Pangaea, and for millennia the hemispheres were separate, evolving almost entirely different... Zobraziť viac
Up until very recently it was believed that in 1491, the year before Columbus landed, the Americas, one-third of the earth's surface, were a near-pristine wilderness inhabited by small, roaming bands of indigenous people.... Zobraziť viac
