An overview of studies on a community of Panamanian figs

Findings from long-term studies of eighteen monoecious fig species and their associated pollinators, parasites, and seed dispersers from a lowland tropical forest community in Panama are summarized. Studies of evolutionary genetics confirm the suggestion from earlier morphological studies that pollinator and non-pollinator wasps, as well as parasitic nematodes, are generally species-specific. Further, phylogenetic reconstructions suggest that these systems are predominated by strict-sense co-evolution among several trophic levels of fig-associated organisms. Studies of population genetics show that fig wasps routinely disperse pollen over surprisingly great distances. Moreover, both the number of individual fig trees constituting a breeding population and the area that they occupy (>100 km(2)) are among the largest for any plant species known. Studies of factors influencing reproductive success of both the figs and their pollinators indicate that, for any given species, many factors (e.g. number and size of pollinators, resource availability, parasite loads) interact in complex but systematic ways to affect the production of seeds and pollinator wasps. Across species, there are repeated patterns of associations among characters such as average number of pollinators per fruit, pollinator sex ratios, nematode virulence, fruit size, fruit colour, physiological properties of the fruit, taxa of associated seed dispersers and degree of synchrony of fruit ripening that imply causal, adaptive linkages and trade-offs among these characters. Collectively, these studies suggest the critical role for comparative work of many species, preferably at many sites, in the understanding of this complex mutualism.