Evolution of increased longevity and slowed ageing in a genus of tropical butterfly.

Evolution has given rise to lifespans in extant species ranging from days to centuries. Given that mechanisms of ageing are highly conserved, studying long-lived lineages across the animal kingdom could yield insights relevant for healthy ageing in humans. The long lifespans reported for the Heliconius butterfly genus position it as a promising new model system for such studies, but its potential is limited by a paucity of available data. Here, we collate data from commercial butterfly houses, mark-release-recapture studies, and insectary populations to reveal the evolution of a three-fold lifespan extension in Heliconius over their close relatives in the Heliconiini tribe, with maximum lifespans in some species stretching nearly up to a year. We further demonstrate through captive experiments that this lifespan extension is accompanied by slowed actuarial and physiological ageing. Together, these results establish Heliconius as a powerful model for investigating the evolutionary and mechanistic basis of increased longevity.