The oldest sites studied in the project were located in South America, and as a group the average age of the sites was about 2,200 years bp (before the present, which is taken as 1950). The skeletons of Santa Elena, Ecuador, are from sites inhabited about 7,500 years ago. The sites in the area are also characterized by ecological diversity, encompassing a wide range of habitats defined by topography, elevation, and proximity to water resources. This diversity is valuable for investigating possible causes or explanations for variations in health.

As a group, the South Americans studied in this project were reasonably healthy. Both Native Americans on this continent and theEuro-Americans in Ecuador scored above average on the health index despite slow growth in childhood (see Table V.1). Their uniformly low scores on stature were overcome by high results in other areas, particularly hypoplasias and infections. The low stature scores do not mesh with other indicators of early childhood health (hypoplasias and anemia), which suggests that growth failure may have occurred later in childhood, that is, adolescence. Indicators of chronic stresswere virtually absent (scores equal or near 100) at several sites for hypoplasias, anemia, dental disease, and trauma. The group who lived in Brazil was among the healthiest populations in the 65 sites under study.