FIGURE 5.

Variation in Mytilus shell shape, following PCA performed on elliptic Fourier coefficients of lateral views of the right shell valves. The variation explained by the first two principal components (PC1 and PC2) is given as percentages, showing the variation in PC scores for the sampled population (n = 435) as a function of (a) depth and (b) frequency of M. trossulus alleles (MT _AF). Individuals are colour‐coded per group (see colour legends), and the 80% confidence intervals (ellipses) of each group are shown to visualize the separation among individuals across the morphospace. Reconstructed shell outlines at the extremes of the morphospace are shown along each PC axis