Craniometrical variation among South American prehistoric populations: climatic, altitudinal, chronological, and geographic contributions.

The independent contributions of climate, altitude, chronology, and geographic location of archeological sites to craniometrical variation are analyzed in a sample of 1,119 skulls from South America. Geographic location is responsible for the highest proportion of craniometrical variation, followed by climate and altitude. It is concluded that geographic isolation has partially prevented gene flow from counterbalancing craniometrical microdifferentiation produced by founder effect.