Limits to natural selection

We review the various factors that limit adaptation by natural selection. R ecent discussion of constraints on selection and, conversely, of the factor s that enhance "evolvability", have concentrated on the kinds of variation that can be produced. Here, we emphasise that adaptation depends on how the various evolutionary processes shape variation in populations. We survey t he limits that population genetics places on adaptive evolution, and discus s the relationship between disparate literatures. (C) 2000 John Wiley & Son s, Inc.