The desserts and jungles are littered with abandoned ancient cities from civilizations that failed without explanation. The synopsis on the back of the book says that it analysis why the great civilizations declined in terms of changes in their environment. The book starts off at Easter Island where explorers found evidence of an advanced culture demonstrated by the huge statues but the current inhabitants were living in caves and had no idea how the statues got there. The theory of the book is that the people cut down the trees to form a runner network to move the 20foot statues around. The inhabitants cut down all the trees to move statues leaving nothing for building, cooking or building canoes.
The main theme of the book is that once humans progressed past small groups of hunter gathers they began to strain the ability of the land to repair itself. …
