These tropical trees breathe at night to survive drought

Some tropical trees have evolved a clever way to survive drought by taking in carbon dioxide at night, allowing them to keep their pores closed during the hot daytime and conserve water. By comparing three Clusia species, researchers discovered that this water-saving form of photosynthesis, known as CAM, did not arise through a single evolutionary change. Instead, ancient genome duplications followed by millions of years of genetic reshuffling produced strikingly different strategies, from strong CAM to stress-triggered and hybrid forms.