Sexual dimorphism in prehispanic populations of the Cochabamba Valleys, Bolivia

Abstract

The expression of sexual dimorphism may vary across time and space, as well as within and between populations depending on genetic and environmental factors that influence growth and development. The objective of the present work is to contribute to the knowledge of factors that determine the physical characteristics of ancient human groups in the eastern valleys of Cochabamba?a key region for cultural development, inter-regional interaction with northern Chile and northwest Argentina, and their noticeable role in the settlement of the south central Andean region. This paper analyzes the differences between males and females crania representing ancient human groups that inhabited the eastern valleys of Cochabamba, Bolivia. Thirty-one craniometric variables are analyzed from a sample of 234 individuals. Differences are evaluated using univariate analysis by ANOVA and multivariate discriminant analysis. The results indicate the existence of higher mean values in males compared to females in most cranial measurements (mean difference 5.3%). The discriminant analysis also reveals a significant morphological difference exists between sexes. Furthermore, by means of the discriminant function, the reclassification of correct sex was 99% of cases. This information indicates that members of this population could live in optimal conditions, with adequate resources to ensure growth and development and normal expression of the phenotype of each sex.