Fig. 4

PLA2 activity reconstructed using linear parsimony on a phylogeny [1] of 16 of the 17 genera tested (27 of the 37 species; Hemiaspis has no PLA2 data). The Y-axis represents millions of years before present. Values had 1 added before log transformation (to avoid attempting to log 0 values, as any species with activity below the threshold of detection of 0.5 –unlogged value -was allocated a score of 0). Dotted vertical lines separate clades. Warmer colours (red) show higher activity, black is no activity. White line on lower left of the graph is due to Hemaispis having no data