Author: Ellsworth Huntington
Man could not stay there forever. He was bound to spread to new regions, partly because of his innate migratory tendency and partly because of Nature's stern urgency.
The evidence points to central Asia as man's original home, for the general movement of human migrations has been outward from that region and not inward.
In fact, the history of North America has been perhaps more profoundly influenced by man's inheritance from his past homes than by the physical features of his present home.
Geologists are rapidly becoming convinced that the mammals spread from their central Asian point of origin largely because of great variations in climate.