Geographical distribution of the study populations.

<p>The 89 populations are presented in three groups according to andromorph frequencies. Average frequencies are given when populations were sampled in multiple years. Numbers one to eight indicate populations where specimens were collected for quantification of physiological parameters (further details of these populations are provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032648#pone-0032648-t001" target="_blank">Table 1</a>).