Morphological-environmental association recovered in the PLS analyses. Scatterplots of the single set of PLS axes for the analysis on size (a), and the first (b) and second (c) set of PLS axes for the analysis on uncorrected shape (results for the size-corrected shape data were similar; not shown). Although PLS analyses were run on population-averaged data, the extent of local intra-population variability is depicted as vertical lines below and above each population score, with the line lengths determined by the minimum and maximum individual scores obtained for each population when all individuals are projected onto each morphological PLS component. In (d) the morphological changes associated with the PLS axes shown in (b) and (c) are summarized by comparing the skull regions associated with each PLS (in black) with the overall mean shape of the entire sample (in grey). Scatterplot symbols follow Figure 2.
Alvarado-Serrano et al. BMC Evolutionary Biology 2013 13:160 doi:10.1186/1471-2148-13-160