FIGURE 2.

Expected changes in allelic frequency for the band polymorphism in Littorina fabalis for the Spanish population of Abelleira assuming genetic drift (Equation 1) in main text). Each dot represents the allelic frequency for the banded polymorphism observed in the year under the assumption of the Hardy–Weinberg equilibrium. The bars indicate the 95% confidence interval of the expected frequencies under genetic drift for the next year, using the minimum (a), mean (b), and maximum (c) estimated values of effective population size (394, 600, and 1,076, respectively)