Figure 1.

Trait mapping on the attine phylogeny. The transition indicated on the phylogeny corresponds to both the evolution of polyandry, as well as to the reduction of MAGs in the monophyletic leafcutter clade including Acromyrmex and Atta. Representative dissections of males, illustrating the primitive and derived morphologies, are shown alongside the phylogeny. An outgroup, the fire ants (Solenopsis) has been included for an informal comparison. AG = accessory glands, SV = seminal vesicles. Note that Ac. volcanus does not have accessory glands.