Structure analysis of the La Guajira-Colombia population: a genetic, demographic and genealogical overview

This study examined whether cultural factors, as compared to geographical distance, have produced a population sub-structure among different groups from the La Guajira population (Amerindian Wayúu and other resident groups) that co-exist within the same region.

The aims of this study were to analyse this population to discover whether cultural barriers result in the sub-structure, to evaluate whether there is a genetic drift effect and to describe migration dynamics using a genetic, genealogical and demographic approach.

This study examined a sample of 290 individuals who were grouped based on a genealogical criterion to distinguish between native individuals and migrants.

Using demographic information, the age and gender structure of the population and genetic drift estimators were analysed. Using 15 autosomal microsatellites, heterozygosity, Hardy-Weinberg equilibrium (HWE), inbreeding, sub-structure, recent migration rate and genetic relationships were also evaluated using a Principal Component analysis (PCA) using reference populations.

La Guajira is a young population that is growing and exposed to a moderate effect of genetic drift (Neme 11.903). The Wayúu are highly diverse (Ho 0.727) and different from other groups, with the exception of Wayúu-Guajiro. This trend was also observed in other Amerindian populations.

This study found a high level of admixture and gene flow within the Wayúu population despite cultural differences. Thus, although the Wayúu population differs from other population groups, it is not an isolated population.