80:3.8

About fifteen thousand years ago the Alpine forests were spreading extensively. The European hunters were being driven to the river valleys and to the seashores by the same climatic coercion that had turned the world’s happy hunting grounds into dry and barren deserts. As the rain winds shifted to the north, the great open grazing lands of Europe became covered by forests. These great and relatively sudden climatic modifications drove the races of Europe to change from open-space hunters to herders, and in some measure to fishers and tillers of the soil.