Accelerating homogenization of mutualistic interactions in the global plant-frugivore meta-network

We studied how introduced species impact plant-frugivore networks and their biogeographic patterns. By assembling 410 plant-frugivore networks recorded around the world over the past 75 years, we found that the proportion of interactions involving introduced partners has increased seven-fold over this timeframe and is eight times higher in the most versus least anthropogenically modified environments. Introduced species significantly blur natural biogeographic patterns in the meta-network that is comprised of all interactions observed within local networks. This reduces the average degrees of separation among species by a third. This accelerating pattern may redirect coevolution and result in functional homogenization among mutualists.