Markers of Genetic Variation Among the Waorani Indians of the Ecuadorian Amazon Headwaters

Until recently, the Waorani Indians of Ecuador's Amazon headwaters maintained a fierce resistance to all intruders into their territory, and as a result of their actions and reputations a population of 600 people controlled a very large territory (about 8,000 square miles). The isolation of the Waorani has resulted in a large linguistic and genetic distance from their neighbors. Our survey of red cell enzymes, immunoglobulin allotypes, and dermatoglyphics demonstrates that the Waorani are a highly inbred and homogeneous population. Of 18 red cell enzymes studied, the Waorani have a limited polymorphism for only 6. Only two Gm haplotypes (Gm1,2,17,21, Gm1,17,21) were found and 60% of those tested were homozygous for the Gm1,17,21 haplotype. All individuals were A2m (1) and 95% of these were homozygous. The Waorani's dermatoglyphic traits fell within the wide range found among other South American Indians with close affinity to the Ecuadorian Jivaro group. Despite the limitations of these genetic systems, they demonstrate that the Waorani share limited genetic traits with the neighboring Jivaro Indians and are isolated from other tribal populations in South America.