The cactus on your desk is an evolution speed machine

The cactus on your windowsill may grow slowly, but new research shows that cacti are surprisingly fast at creating new species. Biologists have long thought that pollinators and specialized flowers drive the formation of new plant species. But scientists at the University of Reading have found that in cacti, the secret lies in how quickly flowers change shape, rather than how big the flowers grow or which animal pollinates them.