Bars in the upper part of the diagram represent mean amylase activities in saliva of corresponding primate species (indicated by the dotted lines). Orange dots in the branches of the phylogenetic tree show the presumed occurrences of gene duplication events. The red X indicates a likely gene loss event. Haploid amylase gene copy numbers are indicated in parentheses above the species name. The copy numbers determined through genotyping by ddPCR are shown in black round parentheses, while those based on reference genomes are shown in gray square brackets. Phylogenetic branches are colored according to dietary preferences (see boxed legend). The upper boxed section is a zoomed-in version of the tree. Abbreviations: G.M., green monkey; V, vervet; A.S., Allen’s swamp monkey; O.W.M., Old World monkeys.