Multi-locus phylogenetic analysis of neotropical figs does not support co-speciation with the pollinators: The importance of systematic scale in fig/wasp cophylogenetic studies

For 18 species of Panamanian Ficus, representing both basal (Pharmacosycea; 4 spp.) and derived (Urostigma, Americana; 14 spp.) sections, we sampled multiple individuals per species and analyzed sequence data from multiple (3) genetic markers (tpi, g3pdh, ITS). In contrast to previous phylogenetic studies of figs, this sampling design allowed us to evaluate the degree to which different alleles within loci, and different loci within individual species suggest consistent phylogenetic relationships among both distantly and closely related figs. We found multiple instances within both tpi and g3pdh genes in which different haplotypes were not monophyletic by species. Haplotype and reconciliation analyses suggested that genetic exchange among closely related figs is necessary to fully explain the patterns. In contrast, analyses of multiple loci from multiple individuals in the wasps are monophyletic by species, producing a well resolved species phylogeny. Although combining fig genetic data sets produced a resolved and robust fig topology, no fig phylogenies based on either combined or individual gene trees showed any significant correspondence with the wasp tree. Recent studies have shown that many of the fig species considered here have multiple pollinators and several share genetically indistinguishable pollinators. Together with these genetic results, it appears that a strict co-speciation model does not adequately describe the general evolutionary dynamics of the fig/wasp mutualism, particularly for sympatric, closely related species (within section). Importantly, these results emphasize the need to consider multiple genes, multiple individuals, and systematic scale in order to conduct and interpret robust co-phylogenetic studies of figs and their pollinating wasps.