Chapter 12 (Part B) Bivariate drift and stabilizing selection

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Figure 12.2 The role of the adaptive landscape in shaping the results of drift-selection balance. The 95% confidence ellipse for genetic values is shown in blue and represents the G-matrix. The adaptive landscape is bivariate stabilizing in all cases and is represented by its 25% confidence ellipse in red. Such a low level ellipse must be employed because the limits of the 95% ellipse would be far outside the scale limits of the figure. The limiting pattern for the dispersion of lineage means is represented by its 95% confidence ellipse in purple. In each panel the animation shows 5 replicate trait means evolving for 1,000 generations under the conditions specified in each panel. (a) Very weak stabilizing selection with strong positive selectional correlation and no genetic correlation. (b) Very weak stabilizing selection with strong positive selectional correlation and a strong positive genetic correlation. (c) Strong stabilizing selection with positive selectional correlation and positive genetic correlation. (d) Strong stabilizing selection with strong positive selectional correlation and a strong negative genetic correlation. (e) Strong stabilizing selection with no selectional correlation and no genetic correlation.