Figure 2

Skull size and shape variability in A . mollis. Scatterplots of all sampled individuals according to their centroid size (a) and their scores on the first two between-groups principal components (BG-PCA) of uncorrected (b) and size-corrected shape (c) (see Methods for details). Individuals from the highest ecosystem (i.e., Central Andean wet puna) are surrounded by a minimum convex hull to facilitate comparison between scatterplots. In addition, in order to illustrate the amount of intrapopulation variance, the position of individuals from two arbitrarily selected populations are highlighted in blue and red (populations 9 and 14, respectively; see Appendix) as an example in an inset in each plot. Symbols are based on two proxies of environmental variation, the elevation and ecosystem (abbreviations as in Figure 1) in which each specimen was sampled.