The ant phylogeny (brown, attine ants in red brown) is genome-based, whereas the cultivar phylogeny (grey) is derived from transcriptomic data. A. cephalotes and A. colombica share the same fungal symbiont species L. gongylophorus70. Only the closest sequenced outgroup, the fire ant S. invicta, is depicted. Full phylogenies including additional ant and free-living fungal outgroups are given in Supplementary Figs 8–11. Error bars (top) indicate minimum and maximum time estimates. The character matrix (right) summarizes key morphological, behavioural and life-history traits across the three major agricultural transitions (yellow, light green and darker green background). Approximate maximum colony sizes are given as powers of 10; queen-insemination status as singly mated (S) or multiply mated (M)13; worker caste polymorphism as 1 (monomorphic), 2 (dimorphic: small and large workers) and>3 (polymorphic, including also a morphologically distinct soldier caste)9. Lower attine cultivars are simple dikaryotic mycelia (ploidy 2), whereas fully domesticated higher attine cultivars have polynucleate cells with marginal degrees of genetic chimerism (2<n<3) or substantial chimeric allopolyploidy (5<n<7) (ref. 14). See Supplementary Methods for details. Photographs: Atta leaf-cutting behaviour (D.R.N.) and a fungal staphyla with gongylidia (courtesy J.T. Høeg).