The Economist looks at an intriguing research discovery: "The one sure way to prolong an animal's life is, paradoxically, to starve it. 'Caloric restriction', as it is known in the trade, works for everything from threadworms to mammals (people included, as far as can be ascertained without the luxury of controlled experiments). So it is no surprise that it also works for a group of small creatures known as rotifers. ... What makes this news is that the offspring of the rotifers in question also lived longer than normal. And that - the inheritance of an acquired characteristic - is quite startling. ... the offspring of calorie-restricted mothers have more catalase than those of mothers who were fed without restriction. The researchers also detected higher levels of the enzyme in the eggs of calorie-restricted mothers, so it could be that their offspring are simply endowed with the stuff. A more intriguing possibility, though, is that the relevant genes are affected by epigenesis, a process in which chemicals attached to the DNA control its activity. Epigenetic modifications are often retained when cells divide, and can sometimes be passed on to offspring." You'll recall that catalase gene engineered to localize in mitochondria can be used to extend life in mice. Researchers will now have to check to see if mammals reproduce any of this inherited catalase effect seen in rotifers.