The invertebrate model organisms continue to be engines of discovery in aging research. Recent work with Drosophila stem cells has thrown light on their human equivalents, and on the role of stem cells and their niches in the decline in fecundity with age. Inspired by observations of aging in bacteria and yeast, a new theoretical study has revealed evolutionary forces that could favour asymmetry in the distribution of damaged cell constituents at division, and hence pave the way for the evolution of aging and selective maintenance of integrity of the germ line. Mechanisms of nutrient sensing and cell signalling in the response of lifespan to dietary restriction have been elucidated. Powerful invertebrate models of human aging-related disease have been produced, and used to start to understand how the aging process acts as a risk factor for disease. In the near future, studies of invertebrate aging are likely to move away from an exclusive reliance on genetic manipulation towards a more biochemical and physiological understanding of these systems.