Gene family expansions and contractions during the evolutionary history of the Arthropoda with a focus on the Copepoda

Phylogenetic reconstruction of 13 high-quality arthropod genomes was performed using RAxML based on concatenated single-copy orthologous genes. All nodes show bootstrap values of 100%, except for two nodes with green rectangles, which have values of 66% (left node) and 60% (right node). The three red dots represent time calibrated nodes, with confidence time intervals retrieved from the TimeTree database and applied in MCMCTree. Mean estimated divergence time is shown at each node with numbers in brackets indicating the interval containing the 95% highest posterior densities. The numbers of expanded gene families (in blue) and contracted gene families (in red) are shown on the branch tips and next to each node. MYA, millions of years ago.