Tylor's scheme was, of course, far too simple, for it was soon apparent that the biological and cultural realities of human societies were far more complex.

While many archaeologists studied Stone Age axes, and the great rock shelters and caves occupied by Arctic hunters during the Great Ice Age, the most sensational discoveries were those that unearthed hitherto unknown early civilizations.

These civilizations came from Egypt, Mesopotamia, Greece, and Central America.