Figure 8.

The probability that a surviving parent in one niche was born in a different niche, plotted against the within-niche variance in underlying preference, var(a). Solid line: symmetric case, c₀ = c₁ = 0.5; dashed lines: asymmetric case, c₀ = 0.2, c₁ = 0.8. The upper dashed line shows the chance that a parent in the smaller niche came from elsewhere, and the lower dashed line, the chance that a parent in the larger niche came from elsewhere. The long dashed line at the centre shows the weighted average of these two. This assumes the infinitesimal model, which has a Gaussian solution (equation (4.2)).