LifeLife's other mystery: Why biology's building blocks are so lop-sidedMost molecules exist in mirror-image forms, and yet life prefers one over the other. How this bias began and why it persisted is one of the most baffling questions in biology – but now we have an answerFeatures
LifeSome starfish-like animals see without eyes by changing body colour Some brittlestars, close relatives of starfish and sea urchins, can work out where light is coming from by changing the colour of their bodies News