Mutualists with attitude: coevolving fig wasps and figs

The intimate mutualism between fig wasps and figs has long captivated biologists, and new phylogenies are now uncovering its evolutionary history. Fig-pollinating wasps evolved just once, but fig parasitism has evolved repeatedly and convergently. Figs and their pollinators appear to have co-speciated considerably, but not invariably, because the famous one-to-one rule of specificity is often broken. Some key traits of figs and pollinators show impressive correlated evolution, but the resolution of conflicts that threaten the stability of the mutualism remains controversial.