Mitochondrial DNA analysis reveals substanial Native American ancestry in Puerto Rico

Human Biology, Aug 2001 by Martinez-Cruzado, J C, Toro-Labrador, G, Ho-Fung, V, Estevez-Montero, M A, Et al

Abstract To estimate the maternal contribution of Native Americans to the human gene pool of Puerto Ricans-a population of mixed African, European, and Amerindian ancestry-the mtDNAs of two sample sets were screened for restriction fragment length polymorphisms (RFLPs) defining the four major Native American haplogroups. The sample set collected from people who claimed to have a maternal ancestor with Native American physiognomic traits had a statistically significant higher frequency of Native American mtDNAs (69.6%) than did the unbiased sample set (52.6%). This higher frequency suggests that, despite the fact that the native Taino culture has been extinct for centuries, the Taino contribution to the current population is considerable and some of the Taino physiognomic traits are still present. Native American haplogroup frequency analysis shows a highly structured distribution, suggesting that the contribution of Native Americans foreign to Puerto Rico is minimal. Haplogroups A and C cover 56.0% and 35.6% of the Native American mtDNAs, respectively. No haplogroup D mtDNAs were found. Most of the linguistic, biological, and cultural evidence suggests that the Ceramic culture of the Tainos originated in or close to the Yanomama territory in the Amazon. However, the absence of haplogroup A in the Yanomami suggests that the Yanomami are not the only Taino ancestors.

KEY WORDS: NATIVE AMERICAN MTDNA HAPLOGROUPS, TAINOS, HISTORICAL NIGRA_ TION

This study seeks to contribute to our knowledge about the maternal contribution of Native Americans to the gene pool of Puerto Ricans, a people of mixed African, European, and Amerindian ancestry, and to investigate the migration history of the extinct Tainos, the native people of Puerto Rico that were subjugated by the Spaniards.

Archaeological evidence shows that the Greater Antilles were already inhabited 8000 years ago by the Archaic culture, nomads who relied on shellfish, fish, and game for their subsistence (Rouse 1992). It is not known whether they migrated to the Antilles from Venezuela or from the peninsulas of Yucatan or Florida. However, from most of the linguistic, biological, and cultural evidence, it is apparent that the Ceramic culture that arrived in Puerto Rico 2200 years before the present (YBP) originated in South America, in or close to the territory occupied today by the Yanomami. The Taino language belongs to the Arawakan family of languages. From the distribution of the Arawakan family of languages, Arawakan speakers have been inferred to have originated in the South American lowlands of the Amazon Basin (Noble 1965). More recently, linguists have proposed that the Proto-Arawakan speakers moved along north of the Negro River, passed through the Casiquiare Canal, and descended the Orinoco River, along the way producing the Proto-Maipuran language, which gave rise to the ProtoMaipuran subfamily of languages to which the Arawak (Lokono) and Taino languages belong (Rouse 1992).

Similarly, using biological traits, Imbelloni (1938) traced the origin of the Taino people from the Guyana lowlands and the Orinoco Valley into Amazonia. In addition, the cultural ancestry of the Taino Indians may be traced back at least to the Ronquinan Saladoid people along the Orinoco River up to its junction with the Apure River. From there, however, they could have come from the west via the Apure and Meta Rivers or from the Amazon by the Negro River (Rouse 1992). Hence, the region in Venezuela occupied by the Yanomami, bordered by the Orinoco to the north and the Casiquiare to the west, is located within the path probably taken by the Taino ancestors in their migration to the Orinoco lowlands.

Little is known about the genetic contribution to Puerto Ricans of the Tainos or Native Americans in general. The native population of Puerto Rico was decimated in the 16th century as a consequence of the Spanish colonization. However, Indian towns existed on the coast two decades after the start of the Spanish colonization in 1508 (Tapia 1854). Upon their emancipation in 1542, many of the remaining Taino Indians stayed in the mountains in the central region of the island and were slowly assimilated through the following decades or centuries by the settler population.

The genetic contribution of the Taino Indians is a matter of speculation. By 1530, gold was no longer found in quantities adequate for mining, and the gold rush that developed in other colonies of Spain like Mexico and Peru had severely reduced the mostly European settler population. The settler population remained low for centuries, thus probably contributing significantly to a higher relative abundance of Native American genotypes in the people that developed into Puerto Ricans than most historical accounts would imply. The 1777 census reported a total of only 70,210 inhabitants in Puerto Rico. These were classified into 31,951 whites, 24,164 free "pardos" (light-skinned mixes mostly of Indian and white ancestry), 4747 free blacks, 4249 black slaves, 3343 "mulato" (mixes of black and white ancestry) slaves, and 1756 pure Indians.