The genealogy of Da. Isabel de Jimenez. An approach to the first phase   of admixture in Costa Rica / La genealogia de Da. Isabel de Jimenez. Una   aproximacion a la primera fase del mestizaje en Costa Rica
  Traditionally the Costa Rican historians and genealogists have interpreted that the Spanish ruling elite emerged after the conquest was exclusively of European origin. On the other side, recent technological advances in Genetics give us the opportunity to approach the study of pedigrees from a new perspective, examining alive people and simultaneously collating the historical information of their ancestors. In this paper, a complete matrilineal genealogy was reconstructed from nowadays "white" Costa Ricans to their ancestors in the early Colonial society (XVI century). It was compared the correlation between ethnic affiliations deduced from historical records with the genetic inheritance from maternal lineages. The MtDNA lineage observed corresponds to a Native American ancestry. These results show that some Amerindian gene flow into the Spanish group must have occurred since the first generation of Colonial society, a finding that contrasts with the prevailing ideas that the Spanish elite avoided the intermarriage with other ethnic groups. Examples like this one confirm that miscegenation began early in Costa Rica. So, those who considered themselves "Spaniards" in the late colonial era, were actually biologically mestizos. It is widely accepted, that the general Costa Rican population is the result of an admixture process between Europeans, Amerindians and Africans. 
Bernal Morera-Brenes, Ramon Villegas-Palma, Mauricio Melendez-Obando
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