Figure 1.

Illustration of our main model assumptions. (A) Phenotypic evolution in the moving-optimum model: The black curve and colored circles give the distribution of phenotypes for three different snapshots in time for a population that adapts to a time-dependent phenotypic optimum (green circles) under Gaussian stabilizing selection (see equation). Note that the population mean phenotype typically lags behind the optimum. (B) The biallelic infinite-sites model: Each mutation creates a new allele at a unique site. (C) The focal-locus genetic-background model used in our analytical approximation (Lande 1983).