• The Word article about junk DNA in 19 November issue (p 54) wrongly stated that the human genome contains a greater proportion of junk DNA than any other species. In fact, the ratio of junk DNA to protein-coding DNA is higher in certain other species, notably some amphibians, than it is in humans.
• The citation in our recent article about faltering currents in the North Atlantic was incorrect (3 December, p 6). It should have been Nature, vol 438, p 655.
