Timetree of Arthropoda. The tree includes all species in which Crmar2 and Mariner-5 were found as well as most closely related species for which whole genome sequences are available in Genbank. Phylogenetic relationships are taken from Tamura et al., Regier et al. , Sharkey  and Regier et al. . Divergence times are taken from Hedges et al.. Divergence times between D. bipectinata and D. ananassae, between D. biarmipes and other Drosophila species, between Dendroctonus ponderosae and Tribolium castaneum, between A. vulgare and Daphnia pulex, and between H. saltator and Nasonia vitripennis are unknown and have therefore been set at arbitrary values for illustrative purposes.