Evolutionary ecology of symbiotic ant-plant relationships

Abstract.--A tabular survey of ant-plant symbioses worldwide summarizes aspects of the evolutionary ecology of these associations. Remarkable similarities between ant-plant symbioses in disjunct tropical regions result from convergent and parallel evolution of similarly preadapted ants and plants. Competition among ants has driven evolutionary specialization in plant-ants and is the principal factor accounting for parallelism and convergence. As habitat specialization accompanied the evolutionary radiation of many myrmecophytes, frequent host shifts and de novo colonizations by habitat-specific ants both inhibited species-specific coevolution and co-cladogenesis, and magnified the diversity of mutualistic partners.