A recent study of Mitochondrial DNA (mtDNA) from 800 individuals found 61.1% as having Amerindian maternal mtDNA, 26.4% as having African maternal mtDNA, and 12.5% as having Caucasian maternal mtDNA.[29] Conversely, patrilineal input, as indicated by the Y chromosome, showed that 70% of all Puerto Rican males have inherited Y chromosome DNA from a male European ancestor, 20% have inherited Y chromosome DNA from a male African ancestor, and fewer than 10% have inherited Y chromosome DNA from a male Amerindian ancestor. In summary, the results suggest that the three largest components of the Puerto Rican genetic pool are European/Caucasian, Amerindian, and African, evidently in that order.

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