Revista chilena de historia natural
Print version ISSN 0716-078X
COCILOVO, JOSÉ A. et al. The spatial structure of the archaic human population of the north coast of Chile (5000-3000 BP) deduced by the statistical analysis of skull metric and not metric traits. Rev. chil. hist. nat. [online]. 2004, vol.77, n.4, pp. 679-693. ISSN 0716-078X. doi: 10.4067/S0716-078X2004000400010.
In this paper we determine the unit or most probable diversity for the archaic groups of Northern coast of Chile and infer the microevolutionary factors that determined the existence of an earlier structuring of the population. Metric (177 non-deformed individuals) and non-metric (288 individuals) features were recorded for samples from the sites of Morro 1-1/6, Morro Arica Uhle (Arid Northern Chile), El Cerrito and Punta de Teatinos (Semiarid Northern Chile). The data was processed by means of contingency tables and MMD distances analysis for discret traits and univariate analysis of variance, principal component analysis, discriminant analysis and calculation of D2 values for metric features. An evaluation of the non-metric traits distribution provides initial proof for the true existence of a structured Archaic coastal population based on the differences found amongst the samples. This spatial structure is supported by the distribution of distinct discreet traits as well as the specific frequencies within each group but without evidencing any apparent tendencies from north to south. Evidence seems to indicate the action of random mechanisms and the presence of phases in the same evolutionary process starting, maybe hundreds of generations previously, from a much older common ancestral population that contained most of the genetic variation observed. The analysis of metric feature distributions provided similar results. Four phenotypic models were segregated and represented by Morro 1-1/6, Morro of Arica Uhle, El Cerrito and Punta de Teatinos. This particular configuration is the product of evolutionary forces determined the morphological differences between both regions (North and South) by isolation and genetic change as well as the emergence of lines of kin-related individuals that were buried in different cemeteries or in specific sectors within the same funerary burial in these same regions.
Keywords : Archaic Northern Chile Period; microevolution of human populations.