Evidence of behavioral co-option from context-dependent variation in mandible use in trap-jaw ants (Odontomachus spp.)

摘要: Evolutionary co-option of existing structures for new functions is a powerful yet understudied mechanism generating novelty. Trap-jaw ants the predatory genus Odontomachus are capable some fastest self-propelled appendage movements ever recorded; their devastating strikes not only used to disable and capture prey, but produce enough force launch into air. We tested four species in variety behavioral contexts examine if mandibles have been co-opted an escape through ballistic propulsion. found that nest proximity makes no difference interactions with prey size has strong influence on suite behaviors employed by ants. In trials involving potential threat (another trap-jaw ant species), vertical jumps were significantly more common acting as intruders than residents (i.e. dangerous context), while horizontal occurred at same rate both contexts. Additionally, jump trajectories heavily influenced angle which substrate was struck appear be under little control ant. conclude may accidental side-effects against hard surfaces, likely intentional defensive from original prey-gathering food-processing jaws.