EcoRI, RsaI, and MspI RFLPs of the COL1A2 gene were analyzed, using the polymerase chain reaction technique, for the first time in a native American population: the Cayapa of Ecuador. These polymorphisms recently turned out to be good anthropological markers, both at the allele and at the haplotype frequency level. These data underline the well-known genetic affinity between the Cayapa and Asian populations. Moreover, our data on DNA polymorphisms agree with the indication of extremely low, if any, gene flow into the Cayapa gene pool from the neighboring black community, as already suggested not only by cultural data but also by protein polymorphisms.