Introduction

The Rocky Mountains of North America blend into the Sierra Madres of Mexico and Central America, which in turn merge into the Andes of South America creating a hemispheric "backbone" that may have helped to channel faunal movements north and south. The location of the tallest mountains along the western margin of the land mass has produced similar vegetational configurations in North and South America. An attempt to produce a coherent synthesis of aboriginal American cultural development requires a certain amount of temerity. Prehistoric cultural development was influenced by the peculiarities of this environmental setting, which facilitated interaction between some regions, stimulated parallel developments in others, and left a few in isolation. The process has been a dynamic one, with climatic fluctuations and landscape modifications exerting varying effects on cultural adaptation during the millennia that man has been a resident of the New World.