Founder effect and number of private polymorphisms observed in Amerindian tribes.

Abstract

Eight examples of private genetic polymorphisms in 12 Amerindian tribes surveyed for electrophoretic variants of an average of 25 proteins were observed. Each of these is presumed to trace to a single mutation. In a preceding communication the statistical theory was developed for estimating the likelihood of such a founder effect in a tribal population of this type. That theory is applied here to the distribution defined by these 8 variants. On the assumption that the phenotypes in question are selectively neutral, such findings are most compatible with a mutation rate of 7 .times. 10-6/locus per generation. This figure applies only to variants that can be detected by the electrophoretic technique.