New submitter jmcdougald.esq sends word that a team of researchers from McGill University has tinkered with the development of a type of ant to produce what they call a 'supersoldier' subcaste — ants that are much larger than average workers but only appear naturally in a few species (abstract). The team's work showed that by exposing the ant larvae to a hormone-like chemical, they could induce 'supersoldier' growth in many more species. "This result suggests that supersoldiers existed in the common ancestor of the entire genus. Even though the supersoldier subcaste eventually disappeared in most species, the ants kept the potential to make it. Because the same hormone sets the fate of both supersoldiers and soldiers, it may not have been possible to completely lose one without compromising the other. ... In some species that evolved later, such as Pheidole obtusospinosa, the supersoldiers became a permanent addition. Whereas most Pheidole species simply evacuate their nests when army ants invade, for some reason P. obtusospinosa find it beneficial to stay, which makes supersoldiers a useful addition to the community."