The fig issue

Figs are remarkable not only for their unusual fruits, quite distinct from any other, but also for their relationship with a group of wasps in which different species pollinate different fig species. The relationship is symbiotic, as the figs are pollinated by the wasps but the insects lay their eggs in some of the flowers that form a food source for the larvae. Tucson, describe the association as 'the most extreme example of specialisation in a plant–pollinator interaction'. But one outstanding question is whether the wasp pollinators have co-diverged among themselves as their fig hosts have also diverged to create the current estimate of 750 species in the tropical and subtropical regions of the world. The new study, analysing comprehensive molecular phylogenetic trees with fossil data to generate independent age estimates for fig and wasp pollinator lineages, suggests that both partners have co-diverged. Identifying 10 pairs of congruent clades, the researchers believe they have the first " unparalleled example of plant–insect co-divergence over geological times, and for at least the past 60 million years. " This ancient link may have pushed both partners along a distinctive path of divergence and mutual dependence.