Beatriz Marcheco-Teruel

Full Professor of Medical Genetics and Senior Researcher, National Centre for Medical Genetics, Medical University of Havana

Biography

Fall 2014: Hutchins Fellowship

Reconstructing the history of admixture and the African Genealogy by DNA studies

Project Description

Reconstructing the history of admixture and the African Genealogy by DNA studies

Cuba is the largest island and most populous country in the Caribbean Sea. It is considered that the presence of its first inhabitants took place about 7600 years ago. In 1492, at the beginning of the Spanish conquest, there were approximately 112000 Indians living in the island, but in the first 50 years of the conquest, the indigenous population was dramatically reduced to few thousand individuals. Since then, the Spaniards brought Indians to the country from Yucatan. In the 17th century and later on African slaves were forced to come mainly from the western coast of Africa, from Cape Blanco until the south of Angola and exceptionally, from the eastern part, starting from towns belonging to the linguistic group Niger-Congo as part of the slave trade. The Hispanic immigration was in turn, a constant process during the conquest, the colonization until the first half of the 20th century. The imbalance in the sexual composition of the immigrants in favor of masculine gender in Africans and overall among the Spaniards (only between 15% and 40% of the Spaniard immigrants were women), favored the miscegenation process. The Cuban population originated since then by the admixture of Amerindian, Spaniards and African.

For the last ten years I have tried to disentangle the admixture proportions for European, African and Native American ancestry of the Cuban population through DNA studies. It has been possible to elucidate that circa 72% of our genes come from European ancestry, 20% from African ancestry and 8% from Native Americans. By studying mitochondrial DNA and Chromosome Y markers we identified a clear sex-biased pattern in the process of gene flow, with a substantially higher European contribution from the paternal side than the maternal side, and higher Native American and African contributions from the maternal side than the paternal side. My next steps are aimed to study where exactly we come from at the intra-continental level. It is my purpose to contrast the evidences from DNA studies with historical data available from successive immigrations. For the Spanish immigration, data regarding their origin and where they come from is much better documented in registries at churches in our main cities; however information regarding ethnical identities of African slaves forced to come in is much more limited. It is my purpose to combine advanced research in genetics and genealogy with historical and social data, as a resource to add new evidences about who we are and where do we come from.

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