Fig. 1

High rate of lineage-specific gene accumulation in aphids relative to all other insect orders. Figures show arthropod phylogenetic relationships, per genome proportions of single copy (blue) and duplicated (red) genes and orthology relationships among arthropod genes based on gene family clustering with MCL [30]. Phylogenetic relationships among arthropod species included for gene family clustering were estimated using RAxML [31] based on a protein alignment of 66 single-copy orthologs found in all taxa. This topology and protein alignment was then used to infer relative divergence times with RelTime [32] under an LG substitution model. Inset shows relative rate of lineage-specific gene accumulation for all included insect orders and comparison with aphids. Error bars show standard deviation of species within a given grouping. Relative rates of lineage-specific gene accumulation were calculated for each species by dividing the number of group specific genes (either order-specific or aphid-specific) by the crown plus stem age for the given group (in relative divergence time)