Pleiotropy and the Preservation of Perfection

David Waxman and Joel Peck

Science 279: 1210-1213 (1998)

Centre for the Study of Evolution, School of Biological Sciences, University of Sussex, Brighton BN1 9QG, Sussex UK

A mathematical model is presented in which a single mutation can affect multiple phenotypic characters, each of which is subject to stabilizing selection. A wide range of mutations is allowed, including ones that produce extremely small phenotypic changes. The analysis shows that, when three or more characters are affected by each mutation, a single optimal genetic sequence may become common. This result provides a hypothesis to explain the low levels of variation and low rates of substitution that are observed at some loci.