that we couldn't figure out having all these fossils. so now having this incredible set of genes from all these different species, and making a thorough analysis, we really could figure it out. it's the availability of food or the insect larvae that live in beds of rivers and streams that drove water shrews into the water. their record dive time is 24 seconds and this research has revealed how these tiny predators' bodies became engineered for this high—speed aquatic hunting. victoria gill, bbc news. next, it's the bbc news at 6pm with george alagiah. but first, it's time for a look at the weather with ben rich. hello there. heat, humidity and thunderstorms feature in the forecast for some, if not all of us over the next 24—48 hours. the humidity really building across the south and the east of the uk, you can see the deep orange colours developing here. lightershades