[Genetic diversity and racial mixture in Amerindians from Costa Rica and Panama].

The genetic diversity of nine Amerindian tribes (Boruca, Bokota, Bribrí, Cabecar, Guatuso, Guaymí, Huetar, Kuna and Teribe) from Costa Rica and Panama were analyzed using 48 loci of enzymatic systems, blood groups and serum proteins. The average heterozygosity (H) and the frequency of polymorphisms (P) for this assemblage are relatively low (H = -0.055; P = 0.217). The genetic differentiation within tribes is also low with the exception of the Cabecar (Gst = 0.049). However it is high between tribes (Gst = 0.073). These populations have some racial admixture and negro and caucasian genes are present in different frequencies (1-30%) depending on their ecological and cultural background. Mating systems and random genetic drift should explain these results. In a broad sense the genetic diversity of these Chibchan tribes are similar to others from South America which use different languages.