Environmental filtering and convergent evolution determine the ecological specialisation of subterranean spiders

1. Ecological specialisation is an important mechanism enhancing species coexistence within a given community. Yet, unravelling the effect of multiple selective evolutionary and ecological factors leading the process of specialisation remains a key challenge in ecology. Subterranean habitats provide highly replicated experimental arenas in which to disentangle the relative contribution of evolutionary history (convergent evolution vs character displacement) and ecological setting (environmental filtering vs competitive exclusion) in driving community assembly.
2. We tested alternative hypotheses about the emergence of ecological specialisation using the radiation of a lineage of sheet-weaver cave-dwelling spiders as model system. We observed that at the local scale, a differential specialisation to cave microhabitats generally parallels moderate levels of morphological similarity and close phylogenetic relatedness among species. Conversely, geographic distance contributed little in expl...