Convergent structure of multitrophic communities over three continents

Abstract

AstractEcological theory predicts that communities using the same resources should have similar structure, but evolutionary constraints on colonisation and niche shifts may hamper such convergence. Multitrophic communities of wasps exploiting fig fruits, which first evolved about 75MYA, do not show long-term 'inheritance' of taxonomic (lineage) composition or species diversity. However, communities on three continents have converged ecologically in the presence and relative abundance of five insect guilds that we define. Some taxa fill the same niches in each community (phylogenetic niche conservatism). However, we show that overall convergence in ecological community structure depends also on a combination of niche shifts by resident lineages and local colonisations of figs by other insect lineages. Our study explores new ground, and develops new heuristic tools, in combining ecology and phylogeny to address patterns in the complex multitrophic communities of insect on plants, which comprise a large part of terrestrial biodiversity.

The Molecular Basis of Phenotypic Convergence

“…The framework developed to study molecular parallelism and phenotypic convergence can also be applied to other disciplines. For example, the core processes that affect evolutionary trajectories have analogs in community ecology (Vellend 2010), and ecological communities can exhibit convergence in trophic structure, species composition, species ecology, or species traits (e.g., Melville et al 2006, Helsen et al 2012, Segar et al 2013). Therefore, a deeper understanding of phenotypic convergence and molecular parallelism could be useful for understanding the factors that influence convergence in composition, assembly, and function of ecological communities.…”

Convergence in Multispecies Interactions

“…For example, convergence appears to be a feature of parasitic fig wasp communities associated with tree species in Africa, Australia and America [76] (Table 1). Species richness differs among the different communities, but the proportions of individual insects within various functional groups are similar across the communities, and these three geographically separated, multi-trophic systems fit the definition of convergent interactions.…”

“…The single evolution of a gene necessary for nodulation likely allowed plants to form associations with bacteria [72], and the different phyla of bacteria likely acquired nitrogenase genes via horizontal transmission [70]; however, the interactions of the plants with different groups of bacteria seem to have emerged independently. Different functional groups of wasps living within figs Communities of parasitoid, pollinator, and galler wasps from different evolutionary lineages live in figs in Australia, Africa, and South America [76].…”

How to be a fig wasp parasite on the fig–fig wasp mutualism

“…Globally [22,48]. The species richness of gallers strongly influences the diversity of parasitoids [12] as in other systems [49].…”