The Puna de Jujuy is a characteristic region of Northwest Argentina, and archaeological evidence shows remarkable development in this area during the period of Regional Development (PRD) or Late period. The aim of this paper is to study the genetic structure of the late population of the Puna de Jujuy (Argentina) using cranial metric traits. The sample comprised 302 adult individuals belonging to six different localities: Agua Caliente, Casabindo, Doncellas, Queta, Río Negro and Sorcuyo. The research included 27 cranial metric variables, a discriminant analysis and the calculation of Mahalanobis' D2 distance and the fixation or genetic divergence index. The results showed little phenotypic differentiation between six locations; 1% of the genetic variation explaind the differences between groups, and the rest represented variations within the group. The sites of Queta and Sorcuyo had lower observed variance values than expected in the model of balance between genetic drift and gene flow, and Agua Caliente showed higher observed variance values than expected. The remaining sites showed values close to the ones expected in the model. The calculated distances suggested that the differentiation between localities was moderate. These results were compared to FST calculated for other local populations. A differential distribution of morphological variability between sites was observed. Agua Caliente, Casabindo, Doncellas and Río Negro showed higher morphological variability due to higher gene flow values, whereas Queta and Sorcuyo showed lower morphological variability.
Biological Affinity, Late period, Genetic Drift, Gene Flow.