From Hillary Shaw, Newport, Shropshire, UK
We can’t communicate with chimps who share 99 per cent of our DNA, says Chris Impey, so what are the chances we could communicate with aliens? However, my computer shares 0 per cent of my DNA and there is two-way communication between me and it. Surely some exchanges are species-independent? I can convey a threat to a cat by looking aggressive, for example. Communication may be algebraic or visual, not necessarily linguistic (27 May, p 27).
