Angiosperms (flowering plants) depend on pollination to reproduce sexually, with pollen transfer facilitated by insects, vertebrates, wind or even water. A key question in angiosperm evolution remains how the ancestors of flowering plants were pollinated and how this may have shifted over time.
Using a robust, dated phylogeny of angiosperms coded with pollination modes at the species level, researchers behind this study set out to reconstruct the evolution of angiosperm pollination and quantify timing and drivers of shifts in modes.
Using so-called correlated Hidden Markov Models based on the phylogeny and pollination modes, they demonstrated that insects were the most likely ancestral pollinators of angiosperms. This was also the case for ancestors of 57 of 64 angiosperm orders.
Their analysis further revealed far more transitions to wind from animal pollination than the reverse. Using GBIF-mediated angiosperm occurrences, the authors found that species with high habitat openness were 20 per cent more likely to be pollinated by animals, whereas wind pollination increased with distance from the equator.
Overall, the analysis estimated that insects have pollinated flowering plants for more than 85 per cent of their evolutionary past, highlighting the long history of interactions between insects and angiosperms still vital to biodiversity today.