Deserts Are Evolution Hotbeds

A phylogenetic study of 774 cactus species finds that variation in floral traits — not specialization on particular pollinators — best explains rapid speciation in the family, and that cacti diversified quickly across the Americas in the last 20–35 million years. Flower size itself does not predict speciation rates; instead, rapid change in floral diversity correlates with lineages branching off. — If deserts are active cradles of rapid evolution rather than static backdrops, conservation priorities and evolutionary theory should shift to account for rapid diversification in arid systems.