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

Background: 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 Wayuu and other resident groups) that co-exist within the same region. Aims: 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. Subjects: This study examined a sample of 290 individuals who were grouped based on a genealogical criterion to distinguish between native individuals and migrants. Materials and methods: 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. Results: La Guajira is a young population that is growing and exposed to a moderate effect of genetic drift (Neme 11.903). The Wayuu are highly diverse (Ho 0.727) and different from other groups, with the exception of Wayuu-Guajiro. This trend was also observed in other Amerindian populations. Conclusion: This study found a high level of admixture and gene flow within the Wayuu population despite cultural differences. Thus, although the Wayuu population differs from other population groups, it is not an isolated population.