Gene clue to how eating a lot less could extend life

Pha-4 is the first gene to be exclusively linked to extending lifespan in response to calorie restriction in animals. Prof Dillin speculated that pha-4, which has an analogue in mice and humans with the Foxa family of genes, probably evolved to protect animals when food was scarce.

Guesser: Andrew Dillin, of the Salk Institute for Biological Studies in California