Evolutionary trajectories of TAS2Rs in Laurasiatheria. Numbers next to nodes denote the number of intact TAS2Rs (complete and partial ones). Numbers on branches denote the number of increases (caused by duplication of genes) and decreases (caused by pseudogenisation and whole-gene deletion). The bracketed ordinal numbers in this figure are used in electric supplementary material table S4, to describe the details of the birth-and-death evolution. To assess the phylogenetic relationships and divergence times of these species, we referred to TimeTree v3.0  and Zhou et al.