Now that scientists have a handful of different ways to extend healthy life span in a range of lower species - largely through manipulation of metabolism - there is much to be learned through experiments that combine and contrast: "Many gene products known to affect lifespan are intimately involved in the control of energy metabolism, including the fuel sensor AMP-activated protein kinase (AMPK). We have shown previously that over-expression of an AMPK [alpha] subunit in Caenorhabditis elegans, designated aak-2, increases lifespan. Here we show the interaction of aak-2 with other pathways known to control aging in worms. Lifespan extension caused by daf-2/insulin-like signaling mutations was highly dependent on aak-2, as was the lifespan extension caused by over-expression of the deacetylase, sir-2.1. ... These results show that aging is controlled by overlapping but distinct pathways." Next up: the same in mice.