NEW WORLD PREHISTORY — WILLEY 



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Figure 1, — Subsistence and settlement type levels in native America: cross section for 

 western North America, Nuclear America, and southern South America. The first 

 appearance of pottery is indicated by the dotted line. 



name Nuclear America refers to the southern two-thirds of Mexico, 

 all of Central America, and Andean and coastal Colombia, Ecuador, 

 and Peru, with adjacent portions of Bolivia. This was the heart- 

 land of native American agriculture and the seat of the two pre- 

 Coliunbian centers of civilization, one in Middle America (Mexico- 

 Guatemala) and the other in Peru-Bolivia [4]. There is a column 

 for each of these two centers on tlie chart, and the colmiin between, 

 headed "Intermediate," refers to what I am calling the "Intermediate 

 area" of southern Central America, Colombia, and Ecuador [5]. To 



