Gradient Evolution of Body Colouration in Surface- and Cave-Dwelling Poecilia mexicana and the Role of Phenotype-Assortative Female Mate Choice

Figure 4

Principal components analysis (PCA). Shown are mean (±SE) principal component scores extracted from PCA on L*a*b* values of all 10 regions on the male body surface for each population. The strongest axis loadings (see main text) are further indicated. Arroyo Bonita (AB, green square), El Azufre (EA, red square), Cueva del Azufre chamber II (CA-II, white square), chamber V (CA-V, grey square), and chamber X (CA-X, black square).