Related Experiment Video
Updated: Jul 22, 2026
07:42
Genome Editing in Astyanax mexicanus Using Transcription Activator-like Effector Nucleases (TALENs)
Published on: June 20, 2016
Gene admixture in the Costa Rican population
B Morera1, R Barrantes, R Marin-Rojas
1Unitat de Biologia Evolutiva, Facultad de Ciencias de la Salut i de la Vida, Universitat Pompeu Fabra, Barcelona, Spain. rbt@cariari.ucr.ac.cr
Annals of Human Genetics
|January 31, 2003
Summary
Costa Rica
Area of Science:
- Population Genetics
- Human Ancestry
Background:
- The Costa Rican population is considered a mix of diverse ancestral groups.
- Understanding the extent of genetic admixture since Spanish colonization is crucial.
Purpose of the Study:
- To quantify the European, Amerindian, and African ancestral proportions in the Costa Rican population.
- To analyze regional variations in genetic admixture across the country.
Main Methods:
- Analysis of 11 classic genetic markers in 2196 individuals from five regions.
- Application of a maximum likelihood approach and principal component (PC) analysis.
Main Results:
- The total population comprises 61% European, 30% Amerindian, and 9% African ancestry.
- Regional variations show higher European ancestry in the North and Central regions.
- Increased Amerindian ancestry in the South and African ancestry in coastal areas were observed.
Conclusions:
- The Costa Rican population is confirmed as trihybrid, reflecting a mix of European, Amerindian, and African gene flow.
- The specific admixture proportions differentiate Costa Rica from other Latin American populations.
Related Concept Videos
01:25What is Population Genetics?
A population is composed of members of the same species that simultaneously live and interact in the same area. When individuals in a population breed, they pass down their genes to their offspring. Many of these genes are polymorphic, meaning that they occur in multiple variants. Such variations of a gene are referred to as alleles. The collective set of all the alleles within a population is known as the gene pool.While some alleles of a given gene might be observed commonly, other variants...
01:09Mutation, Gene Flow, and Genetic Drift
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).Mechanisms of Genetic VariationThe original sources of genetic variation are mutations,...
02:16Genetics of Speciation
Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.The genetics of speciation involves the different traits or isolating mechanisms preventing gene exchange, leading to reproductive isolation. Reproductive isolation can be due to reproductive barriers that have effects either before or after the formation of a zygote. Pre-zygotic mechanisms prevent fertilization from occurring, and post-zygotic mechanisms...
03:33Genetic Drift
Natural selection—probably the most well-known evolutionary mechanism—increases the prevalence of traits that enhance survival and reproduction. However, evolution does not merely propagate favorable traits, nor does it always benefit populations.Life is not fair. A deer grazing contentedly in a field can have her meal cut tragically short by a bolt of lightning. If the doomed doe is one of only three in the population, 1/3 of the population’s gene pool is lost. Random events like this can...
02:39Gene Flow
Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.
01:25Genetic Variation
Genetic variation is the diversity in DNA sequences found among individuals of the same species. This diversity is crucial for a species' survival because it helps organisms adapt to environmental changes. Genetic variation begins with fertilization, where an egg and sperm cell merge. Each of these cells carries 23 chromosomes, up to 46 in the fertilized egg. Chromosomes are long DNA strands that contain genes, the basic units of heredity.
Genes exist in different versions called alleles, which...
Genes exist in different versions called alleles, which...